VICP Registry Case Source Bundle
Canonical URL: https://vicp-registry.org/case/USCOURTS-cofc-1_18-vv-01303
Package ID: USCOURTS-cofc-1_18-vv-01303
Petitioner: Tara Dennington
Filed: 2018-08-28
Decided: 2023-10-06
Vaccine: Tdap
Vaccination date: 2015-08-30
Condition: Guillain-Barré syndrome (GBS)
Outcome: denied
Award amount USD: 

AI-assisted case summary:
Tara Dennington filed a claim alleging that a Tdap vaccine she received on August 30, 2015, caused her to develop Guillain-Barré syndrome (GBS). She had a prior history of GBS in 2005, diagnosed as Miller-Fisher variant, which resulted in significant fatigue and weakness. In 2015, two days after receiving the Tdap vaccine, Dennington experienced numbness and tingling, which she reported as similar to her previous GBS onset. She was treated with IVIG and diagnosed with GBS, though her treating neurologist also considered chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in his differential diagnosis. Petitioner's expert, Dr. Carlo Tornatore, opined that the Tdap vaccine could cause GBS through molecular mimicry and that Dennington's case fit this theory, noting her rapid symptom onset as medically acceptable due to a presumed prior exposure (rechallenge). Respondent's expert, Dr. Timothy Vartanian, disagreed, stating that medical literature did not support a causal link between the Tdap vaccine and GBS, that Dennington's prior GBS diagnosis was not definitively linked to a vaccine, and that her symptom onset was too soon for an adaptive immune response. The Chief Special Master denied entitlement, finding that Dennington failed to establish a reputable medical theory connecting the Tdap vaccine to GBS via molecular mimicry, as her expert did not provide specific evidence linking the two. The Special Master also found the onset timeframe of two days to be medically unacceptable for an autoimmune response. This decision was affirmed on review by the Court of Federal Claims, which agreed that Petitioner failed to establish a specific causal link between the Tdap vaccine and GBS, and that the onset timeframe was not medically acceptable. Therefore, the claim was denied.

Theory of causation field:
Off-Table

Public staged source text:

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DOCUMENT 1: USCOURTS-cofc-1_18-vv-01303-0
Date issued/filed: 2023-04-17
Pages: 28
Docket text: PUBLIC DECISION (Originally filed: 03/23/2023) regarding 59 DECISION of Special Master. Signed by Chief Special Master Brian H. Corcoran. (saj) Service on parties made.
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Case 1:18-vv-01303-ZNS Document 60 Filed 04/17/23 Page 1 of 28
In the United States Court of Federal Claims
OFFICE OF SPECIAL MASTERS
No. 18-1303V
(to be published)
* * * * * * * * * * * * * * * * * * * * * * * * *
TARA DENNINGTON, *
* Chief Special Master Corcoran
*
Petitioner, * Filed: March 23, 2023
*
v. *
*
SECRETARY OF HEALTH *
AND HUMAN SERVICES, *
*
Respondent. *
*
* * * * * * * * * * * * * * * * * * * * * * * * *
Leah VaSahnja Durant, Law Offices of Leah V. Durant, PLLC, Washington, DC, for Petitioner.
Tyler King, U.S. Department of Justice, Washington, DC, for Respondent.
ENTITLEMENT DECISION1
On August 28, 2018, Tara Dennington filed this action seeking compensation under the
National Vaccine Injury Compensation Program (the “Program”).2 ECF No. 1. Petitioner alleges
that a tetanus, diphtheria, and acellular pertussis (“Tdap”) vaccine she received on August 30,
2015, caused her to incur Guillain-Barré syndrome (“GBS”). Id.
The parties have agreed that the matter could reasonably be resolved via ruling on the
record, and filed briefs in support of their respective positions. See Petitioner’s Motion, dated April
1 This Decision will be posted on the United States Court of Federal Claims’ website in accordance with the E-
Government Act of 2002, 44 U.S.C. § 3501 (2012). This means the Decision will be available to anyone with access
to the internet. As provided by 42 U.S.C. § 300aa-12(d)(4)(B), however, the parties may object to the published
Ruling’s inclusion of certain kinds of confidential information. Specifically, under Vaccine Rule 18(b), each party has
fourteen (14) days within which to request redaction “of any information furnished by that party: (1) that is a trade
secret or commercial or financial in substance and is privileged or confidential; or (2) that includes medical files or
similar files, the disclosure of which would constitute a clearly unwarranted invasion of privacy.” Vaccine Rule 18(b).
Otherwise, the entire Decision will be available to the public in its current form. Id.
2 The Vaccine Program comprises Part 2 of the National Childhood Vaccine Injury Act of 1986, Pub. L. No. 99-660,
100 Stat. 3758, codified as amended at 42 U.S.C. §§ 300aa-10 through 34 (2012) [hereinafter “Vaccine Act” or “the
Act”]. Individual section references hereafter will be to § 300aa of the Act (but will omit that statutory prefix).

Case 1:18-vv-01303-ZNS Document 60 Filed 04/17/23 Page 2 of 28
22, 2022 (ECF No. 46) (“Mot.”); Respondent’s Opposition, dated July 7, 2022 (ECF No. 53)
(“Opp.”); Petitioner’s Reply, dated August 1, 2022 (ECF No. 55) (“Reply”). Having reviewed the
above plus the filed medical records, expert reports, and associated literature, I hereby deny an
entitlement award. As discussed in greater detail below, Petitioner has not preponderantly
established that the Tdap vaccine he received could cause GBS, or that it did so to her in a
medically-acceptable timeframe.
I. Fact History
Pre-Vaccination History and Previous GBS Diagnosis
Petitioner had a prior medical history of abdominal pain, allergic rhinitis, gastroesophageal
reflux disease, asthma, obsessive-compulsive disorder, anxiety, and irritable bowel syndrome. Ex.
12 at 7; Ex. 14 at 5–7. Significantly, she had previously suffered from GBS (Miller-Fisher variant)
in 2005, which left her with bilateral hearing loss, weakness and fatigue. Ex. 9 at 42.
Ms. Dennington’s earlier bout of GBS began approximately ten years earlier, in 2005,
when she was 15 years old. Records submitted from this period do not report any vaccine (let alone
a Tdap vaccination) being administered close-in-time to the illness,3 and also indicate that a week
prior to visiting the emergency room, she had “developed a fever with a mild headache and neck
pain.” Ex. 16 at 20, 24–25; Ex. 22.
Petitioner eventually visited South Hermann emergency room and Texas Children’s
Hospital (“TCH”) in Houston, Texas, on August 21, 2005, for complaints of bilateral facial
paralysis, weakness, and ataxia, and was thereafter hospitalized until the end of that month. Ex. 16
at 20, 24–25. While hospitalized, a head CT scan and lumbar puncture were performed. Id. The
CT scan was reportedly normal and the lumbar puncture reportedly showed no white blood cells,
a protein level of 123, and normal glucose. Id. She complained of unsteadiness/dizziness with
lightheadedness that was worse when she sat or stood up. Id. A pediatric neurologist performed a
consultation the following day and expressed the suspicion that Petitioner was suffering from GBS
or possible spinal cord demyelination. Id. An MRI of the spine was normal, however, with no
evidence of demyelination. Ex. 16 at 23.
According to a progress note written on August 24, 2005, Petitioner was diagnosed with
GBS with bulbar involvement and transferred out of the pediatric intensive care unit to the
3 Petitioner filed a record titled “complete Vaccination Records,” but this record does not identify the source of its
information, the entity responsible for creating this record, or the basis for the information included in the chart. Ex.
22. This document indicates that Petitioner received Tdap vaccine doses several times in the several times in the years
before this illness. Id. But the dose administered closest in time to her first GBS diagnosis (in August 2005) occurred
15 months before, in 2004. Petitioner otherwise acknowledges that the record does not establish she received any Tdap
vaccine dose right before onset of her GBS symptoms at this prior time. Mot. at 28.
2

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progressive care unit.4 Ex. 16 at 25. After treatment with IVIG5 she was to be transferred again for
continued rehabilitation. Id. at 25, 27. Petitioner underwent a rehabilitation evaluation at TCH on
August 26, 2005, and the record from it noted no cognitive impairment but difficulty with some
activities of daily living (“ADLs”) due to ataxia. Id. at 27. She also had impaired oral motor
function due to facial weakness but no gagging with oral intake. Id. She was scheduled for
physical, occupational, and speech therapy.6 Id. at 28.
Petitioner saw neurologist Aloysia Schwabe, M.D., of Physical Medicine and
Rehabilitation Services at TCH, for follow-up on October 31, 2005. Ex. 16 at 37. Petitioner
reported persistent fatigue that affected her ability to participate in physical and occupational
therapy. Id. She continued occupational, physical, and speech therapy three times per week. Id.
She demonstrated improved strength and balance and was walking independently. Id. Petitioner
saw Dr. Schwabe again on January 9, 2006, complaining of persistent fatigue since October 2005.
Ex. 16 at 40–41. Her facial weakness persisted into the summer, although her overall motor
function had somewhat improved. Ex. 16 at 44–45. Otherwise, she received physical,
occupational, and speech therapy until she was discharged in April of 2006.
On November 16, 2006, Petitioner returned to TCH for a neurologic follow-up. Ex. 16 at
47. It was noted that she still suffered from a lack of energy and was fatigued easily, with some
lingering facial symptoms despite improvement. Id. Almost three years later,7 on September 11,
2009, Petitioner had another neurology consultation at the Houston Neurological Institute, where
she was seen by neurologist Kathleen Eberle, M.D. Ex. 10 at 1. Dr. Eberle agreed that Petitioner’s
presentation was suggestive of the “Miller Fisher variant of [GBS] and/or Bickerstaff’s brainstem
encephalitis.” Id. An electromyogram (“EMG”)8 performed on January 7, 2010, showed evidence
4 It was reported that prior to her presentation at TCH, Petitioner had a seven-day history of nasal congestion and
headache, and had been diagnosed by her primary care physician as sinusitis and sent home on antibiotic therapy. Ex.
16 at 25. When she developed facial drooping, Petitioner returned to the emergency room and was subsequently
transferred to TCH. Id.
5 Intravenous immunoglobulin (“IVIG”) is a blood product used to treat patients with antibody deficiencies, including
neurological disorders. Clinical Uses of Intravenous Immunoglobulin, NCBI (2005),
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1809480/ (last visited on Mar. 23, 2023).
6 Petitioner provided a letter from Neurodevelopmental Therapy Services (“NTS”) dated September 15, 2005,
indicating that Petitioner was admitted to their clinic on September 6, 2005 for occupational, physical, and speech
therapy. Ex. 21 at 1. NTS indicated that they no longer had records of the services provided as they had been destroyed
in accordance with the state of Texas rules for retention of such records. Id. at 2.
7 There are no records of care filed in this case for the timeframe between November 2006 and September 2009.
8 Electromyography is the process by which “an electrodiagnostic technique for recording the extracellular activity
(action potentials and evoked potentials) of skeletal muscles at rest, during voluntary contractions, and during
electrical stimulation; performed using any of a variety of surface electrodes, needle electrodes, and devices for
amplifying, transmitting, and recording the signals.” Electromyography, Dorland’s Medical Dictionary Online,
https://www.dorlandsonline.com/dorland/definition?id=15854&searchterm=electromyography (last visited Mar. 23,
2023).
3

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of a “chronic sensorimotor neuropathy, predominantly demyelinating.” Id. at 5. That same month,
Dr. Eberle wrote a letter addressed “to whom it may concern” stating that Petitioner had been
diagnosed with a variant of GBS in 2005, and that she had “never achieved full recovery.” Ex. 19
at 1.
2015 Vaccination and GBS Treatment
On August 30, 2015, Petitioner (now 25 years old) was seen at the Kingwood Medical
Center emergency room (“Kingwood”) in Kingwood, Texas for a rash and abscess. Ex. 6 at 29.
Petitioner reported that she had scraped her foot on an old rusty pole and had mild pain, but no
fever, chills, or drainage from her wound. Id. She received the Tdap vaccine and was advised to
keep the wound clean and dry. Id. at 31; Ex. 1 at 1.
Two days later, on September 1, 2015, Petitioner returned to Kingwood with complaints
of numbness and tingling that was worse in her lower extremities. Ex. 6 at 11 (reporting that her
“foot just kinda feels asleep”). She denied chest pain and shortness of breath. Id. She also reported
receiving a tetanus vaccination two days earlier, and that she had a medical history of GBS. Id.
Physical examination did not document any abnormalities. Id. at 12–14. Approximately two hours
after arriving at Kingwood, Petitioner’s mother stated that Petitioner needed to see a neurologist,
and Petitioner and her mother left Kingwood “against medical advice.” Id. at 11–15.
Petitioner presented to TCH that same day. Ex. 8 at 3. She provided a history of numbness
of the left side of the face, leg, and toes. Id. Petitioner’s mother reported that Petitioner had been
seen at TCH in 2005 “with [the] same complaints after [she] received a [t]dap vaccination,” and
was then diagnosed with GBS (although the record as discussed does not indicate she received the
Tdap vaccine in 2005). Id. Petitioner also, however, reported a two-day history of a subjective
fever and nausea earlier in the day. Id. The attending resident noted that it was an “[i]nteresting
presentation of parasthesia and numbness which the patient states was very similar to onset of her
previous episode of [GBS].” Id. Upon examination, she had a normal respiratory exam and no
headaches or neck rigidity. Id. at 3–4. She had full bilateral upper and lower extremity strength
against resistance in all flexors and extensors, but decreased sensation in her left upper and lower
extremities and left face. Id. at 5.
Because Petitioner had transitioned to adult care, she was transferred to Houston Methodist
Hospital, where she was admitted on September 1, 2015, for complaints of weakness and
numbness in her legs for two days after receiving a Tdap vaccination. Ex. 7 at 136–37, Ex. 8 at 6.
Neurologist Robert Smith, M.D., evaluated Petitioner following her admission for possible GBS.
Id. at 140. Upon examination, Petitioner had mild right facial weakness. Id. at 141. Her motor
exam showed full strength in the right upper and lower extremities, but reduced strength in the left
upper and lower extremities. Id. The differential diagnosis included acute disseminated
encephalomyelitis and GBS, along with “possible nonorganic cause of weakness.” Id.
4

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A lumbar puncture done on September 2, 2015, revealed normal protein and glucose and
no oligoclonal bands. Ex. 7 at 302–03, 309. The brain MRI done that same day was also
unremarkable. Id. at 185. However, EMG/NCS testing yielded abnormal results, showing
decreased F-waves. Ex. 9 at 48–49. Dr. Smith initiated treatment with IVIG based on these results
and evidence of decreased reflexes. Ex. 7 at 146.
On September 4, 2015, a note in Petitioner’s neurology evaluation states that Ms.
Dennington had 4+/5 strength in the left upper and lower extremities with normal strength on the
right and a decreased 1+/4 reflex at the left knee, a normal 2+/4 reflex at the right knee, and absent
reflexes at the ankles bilaterally. Ex. 7 at 150. The note also indicated that Petitioner had mild
objective weakness and subjective numbness on the left side and because of her history of a
previous episode of the Miller-Fisher variant of GBS, there was concern about a recurrence and
she was to receive five doses of IVIG. Id.
Evolution of Treatment
Over the course of her treatment with IVIG, Petitioner reported that her symptoms were
improving. Ex. 7 at 151–52, 154. Petitioner was discharged home on September 6, 2015, after
completing five IVIG doses. Id. at 171, 369–70. Her discharge note included a “concern [] for a
possible recurrence of GBS.” Id. at 369–70.
Petitioner followed up with Dr. Smith on October 13, 2015, to evaluate her for chronic
inflammatory demyelinating polyradiculoneuropathy (“CIDP”). Ex. 9 at 39. Dr. Smith noted that
Petitioner was being seen for evaluation of “recurrent GBS vs CIDP, relapsing type after
hospitalization.” Id. He noted that Petitioner’s first episode of weakness occurred ten years prior
following a Tdap vaccination and “presumed viral infection with diarrhea/flulike [sic]
[symptoms].” Id. “Following repeat [Tdap in 2015] . . . [Petitioner] developed identical prodrome
of flu-like symptoms and diarrhea for several days followed by weakness.” Id. Dr. Smith also
noted that Petitioner had recovered from her earlier episode of GBS, “only for recurrent episode
with similar activating stimulus.” Id. He further noted the possibility of a diagnosis of CIDP, with
onset in 2015 with “exacerbation following similar activator.” Id.
Upon examination, Ms. Dennington displayed fatiguing nystagmus, abnormal facial
expression and weakness, decreased hearing to finger rub, decreased reflexes, and decreased
sensation to light touch in all extremities. Ex. 9 at 41. Dr. Smith assessed Petitioner with worsening
CIDP, noting that while Petitioner and her mother do not feel that she has worsened, she had
continued deficits and “slightly worsened proximal weakness” upon examination. Id. at 42. Her
reflexes had returned in the lower extremities, but remained suppressed in the upper extremities.
Id. Dr. Smith prescribed IVIG two days per month and referred Petitioner to physical therapy. Id.
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Petitioner underwent a physical therapy evaluation at Kindred Rehabilitation Hospital on
October 29, 2015. Ex. 2 at 4. She had nerve tingling in her face and muscle weakness. She wanted
to improve her balance and increase her endurance. Id. Petitioner participated in three additional
therapy sessions between November 5 and 12, 2015, and then “discharged herself due to the long
drive to therapy” on November 17, 2015. Id. at 9.
Petitioner followed up with Dr. Smith on December 10, 2015, for bilateral hearing loss,
CIDP, and mild memory loss. Ex. 9 at 35. She had begun IVIG treatment again, and noted that her
previous facial sensory dysesthesias had resolved, with improved limb endurance as well. Id.
However, she continued to have problems maintaining her posture and had problems with balance.
Id. Dr. Smith discussed a neuropsychology referral as Petitioner had “baseline deficits from
previous postvaccination event; though is fully functional.” Id. at 37. Dr. Smith also noted
“Description of Topics Counseled: Vestibular rehabilitation. When is GBS actually CIDP, and
when can therapy for chronic problem help repair in recurrent but inactive process. [Central
nervous system] involvement in post-vaccination [central and peripheral nervous system] injury.”
Id. at 37–38. Dr. Smith gave Petitioner a referral for physical and occupational therapy and ordered
an EMG/NCS. Id.
Petitioner saw Dr. Smith in a follow-up for recurrent GBS on March 16, 2016. Ex. 9 at 31.
Due to insurance reasons, Petitioner was not getting IVIG. Id. She was clinically stable but had
evidence of incomplete resolution of problems with limb posture and endurance. Id. Dr. Smith
noted that Ms. Dennington had a “mildly depressed affect” and on neurologic examination found
ongoing weakness in multiple muscles and muscle groups in the upper and lower extremities. Id.
at 33–34. His assessment was GBS, bilateral hearing loss (due to initial episode of GBS), and mild
memory disturbance from “post episode of post-vaccination GBS+ . . . with balance and memory
changes similar to those from previous episode 10 years earlier.” Id. at 34.
A repeat EMG/NCS on April 6, 2016, showed evidence of a “diffuse polyradiculopathy
with previous denervation and incomplete reinnervation.” Ex. 35 at 7–9. On May 25, 2016, Dr.
Smith noted that “for a variety of reasons” after November, Petitioner was no longer receiving
IVIG. Ex. 9 at 27. However, she had remained stable with slow improvement in strength and
endurance. Id.
In December 2016, Dr. Smith noted that Petitioner’s most recent EMG “documented no
new active lesions (not ongoing CIDP), but still showed evidence of distal demyelination - residual
yet to recover from her most recent episode of weakness.” Ex. 9 at 3. Dr. Smith noted persistent
deficits in fatigue, endurance, and focus, with milder deficits in weakness and sensory function.
Id. at 12. Dr. Smith indicated that he had written a letter documenting Petitioner’s deficits to be
used in her appeal to “government agencies involved in her oversight.” Id. Petitioner’s condition
and assessment at her May 2017 visit with Dr. Smith was essentially unchanged. Id. at 16–25.
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On May 25, 2018, Petitioner had a follow-up visit with Dr. Smith for evaluation of
recurrent GBS. Ex. 9 at 27–30. It noted that she was stable and slowly improving in strength and
duration over the past five months. Id. Physical examination showed weakness of the facial
muscles that was more pronounced on the right resulting in some asymmetry, ongoing weakness
of the extremities, and decreased to absent reflexes except at the knees. Id. Dr. Smith’s assessment
was GBS, though Petitioner “[i]nitially [had] some features suggestive of CIDP. . .” with lower
facial weakness due to recurrent GBS, and bilateral hearing loss after her initial episode of GBS.
Id. at 30.
The most recent visit with Dr. Smith in the records provided was on March 13, 2019. Ex.
20 at 18. Petitioner was no longer working (which had helped to reduce her anxiety level) and was
receiving Social Security disability compensation. Id. at 18–19.
II. Expert Reports
A. Petitioner’s Expert – Carlo Tornatore, M.D.
Dr. Tornatore, a board-certified neurologist, prepared two written reports for Petitioner in
support of the contention that the Tdap vaccine can cause GBS, and that it did so in this case.
Report, dated April 5, 2021, filed as Ex. 36 (ECF No. 38-1) (“Tornatore First Rep.”); Report, dated
January 10, 2022, filed as Ex. 38 (ECF No. 43-1) (“Tornatore Second Rep.”).
Dr. Tornatore graduated from Cornell University with a Bachelor of Arts in Neurobiology,
and attended Georgetown University Medical Center, where he received a Master of Science in
Physiology. Curriculum Vitae, filed as Ex. B on April 5, 2021 (ECF No. 42-21) (“Tornatore CV”)
at 2. He subsequently graduated from medical school at Georgetown University School of
Medicine, completing a residency in the Department of Neurology at Georgetown University
Hospital. Id. He also completed a fellowship in molecular virology at the National Institute of
Health in Bethesda, Maryland. Id. Dr. Tornatore has published multiple articles addressing cell
biology and pathology of demyelinating disorders. Id. at 8–16. Currently, he serves as Professor
and Chairman of the Department of Neurology at Georgetown University Medical Center,
Chairman and Neurologist-in-Chief of the Department of Neurology at Medstar Georgetown
University Hospital in Washington, D.C., and Executive Director of the Multiple Sclerosis Patient
Centered Specialty Home. Tornatore First Rep. at 1.
First Report
Dr. Tornatore opined that Petitioner has GBS, which he defined as an autoimmune
demyelinating neuropathy of the peripheral nervous system. Tornatore First Rep. at 21–22. It is
believed that foreign antigens (e.g., viral or bacterial infection or vaccination) result in activation
7

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of the immune system—a normal mechanism to clear the offending antigen. Id. However, in rare
cases, the activation is misdirected, and both the humoral and cellular arms of the immune system
(the innate and adaptive responses, respectively) attack components of its own nervous system. Id.
In the case of GBS, the target of the immune response is the myelin (and in some cases the axons)
of the peripheral nervous system. Id. The resulting injury is manifested clinically by numbness and
weakness of the extremities, truncal muscles and muscles of the face and neck. Id. Unilateral or
bilateral facial weakness, as in Ms. Dennington’s situation, is very typical of GBS. Id.
Dr. Tornatore went into great detail discussing Ms. Dennington’s medical records in the
context of a GBS diagnosis (with this summation consisting of the majority of his first report).
Tornatore First Rep. at 2–20. He emphasized the fact that Petitioner had experienced two episodes
of GBS—thus, he deemed the best characterization of her diagnosis to be “recurrent GBS.” Id. at
21. Petitioner’s first episode began on August 21, 2005, with characteristics of facial diplegia and
motor weakness, and the second episode was on September 1, 2015, which occurred shortly after
receiving the Tdap vaccine (on August 30, 2015), and was marked with “nearly identical”
symptoms to the first episode. Id.; Ex. 6 at 11–15; Ex. 16 at 20. Petitioner’s EMG results from
September 2, 2015, indicated early acute proximal demyelination and normal cerebrospinal fluid
(“CSF”) protein levels, which was consistent with early GBS, according to Dr. Tornatore.
Tornatore First Rep. at 13–14, 21; Ex. 9 at 48–49; C. Fokke et al., Diagnosis of Guillain-Barré
Syndrome and Validation of Brighton Criteria, Brain 33, 41 (2014), filed as Ex. 50 (ECF No. 57-
1) (“Fokke”). And although one of Petitioner’s treaters (Dr. Smith) felt the 2015 GBS occurrence
had some characteristics of CIDP, Petitioner reached nadir within four weeks of onset—a defining
feature of GBS. Tornatore First Rep. at 21; Ex. 9 at 30, 39, 41.
Next, Dr. Tornatore explained how the Tdap vaccine could theoretically cause GBS.
Tornatore First Rep. at 22–24. The pathogenesis of GBS, Dr. Tornatore contended, is affected by
molecular mimicry post-exposure to viral or bacterial antigens (which in turn resemble or mimic,
host structures—meaning antibodies to the foreign antigens mistakenly attack the self). Id. at 22;
R. Hughes & D. Cornblath, Guillain-Barré Syndrome, 366 Lancet 1653, 1658 (2005), filed as Ex.
39 (ECF No. 47-1). The concept of molecular mimicry is well-established in immunology.
Tornatore First Rep. at 23; M. B. A. Oldstone, Molecular Mimicry, Microbial Infection, and
Autoimmune Disease: Evolution of the Concept, 296 Current Topics Microbiology & Immunology
1, 3, 13 (2005), filed as Ex. 40 (ECF No. 47-2); T. Komagamine & N. Yuki, Ganglioside Mimicry
as a Cause of Guillain-Barré Syndrome, 5 CNS & Neurological Disorders - Drug Targets 391,
395–96 (2006), filed as Ex. 52 (ECF No. 57-3) (discussing molecular mimicry in the context of
autoimmune neuropathies and Campylobacter jejuni).
Of relevance to the discussion of vaccinations, Dr. Tornatore noted that GBS has been
discussed in association with swine flu and tetanus vaccines. L. Schonberger et al., Guillain-Barré
Syndrome Following Vaccination in the National Influenza Immunization Program, United States,
8

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1976–1977, 110 Am. J. Epidemiology 105, 120–22 (1979), filed as Ex. 42 (ECF No. 47-4)
(“Schonberger”). Additionally, other studies suggest that vaccines other than the flu vaccine can
be associated with GBS. N. Souayah et al., Guillain-Barre Syndrome After Vaccination in United
States: A Report from the CDC/FDA Vaccine Adverse Event Reporting System (1990–2005), 11
Neuromuscular Disease 1, 5 (2009), filed as Ex. 45 (ECF No. 47-7) (“[o]ur results suggest that
vaccines other than influenza vaccine can be associated with GBS.”). He also cites case reports of
autoimmune peripheral neuropathies following other vaccines. F. E. Shaw et al., Postmarketing
Surveillance for Neurologic Adverse Events Reported After Hepatitis B Vaccination, 127 Am. J.
Epidemiology 337, 344–50 (1988), filed as Ex. 44 (ECF No. 47-6) (“Shaw”); M. Khamaisi et al.,
Guillain-Barré Syndrome Following Hepatitis B Vaccination, 22 Clinical & Experimental
Rheumatology 767, 768–69 (2004), filed as Ex. 51 (ECF No. 57-2) (“Khamaisi”). Overall, due to
the recognized biological mechanisms discussed, Dr. Tornatore opined that the Tdap vaccine more
likely than not could result in autoimmune peripheral nerve demyelination clinically presenting as
GBS. Tornatore First Rep. at 24.
Dr. Tornatore maintained that Petitioner’s medical history was consistent with his
causation theory. Tornatore First Rep. at 21. Petitioner had no antecedent events to her second
episode of GBS other than the Tdap vaccination. Id. Additionally, one of Petitioner’s treaters, Dr.
Smith, seemed in records to allude to the possibility of vaccine-induced GBS (despite some
contentions that Ms. Dennington had characteristics of CIDP). Id.; Ex. 9 at 34, 39.
Finally, Dr. Tornatore deemed the timeframe for Petitioner’s symptoms onset—within 48
hours of vaccination—to be medically acceptable. Tornatore First Rep. at 24–25; Ex. 6 at 11–15;
Ex. 7 at 136–37. He opined that since her immune system was previously primed by earlier
exposure to the Tdap vaccine, a quick response to a second antigenic challenge could be anticipated
within 24 hours, so the rapidity with which Ms. Dennington’s symptoms was consistent with that
timeframe. Tornatore First Rep. at 24. To support this assertion, he relied on literature discussing
the acceleration of the immune response after previous exposure, and most notably a piece of
literature cited widely in the Program that is over forty years old, and which I have previously
discussed relies on a flu vaccine that has not generally been administered since the 1970s.
Schonberger at 105 (reviewing the onset of inflammatory demyelinating polyneuropathies
following swine flu vaccination).9
9 Dr. Tornatore also referenced two other items of literature, although one was not filed and the other did not reference
the assertions he claimed (by my estimation, and due to the misfiling of specific pages). Tornatore First Rep. at 25;
See generally Institute of Medicine, Adverse Effects of Vaccines: Evidence and Causality 39, 39–54 (Kathleen R.
Stratton et al., eds., 2011), filed as Ex. 47 (ECF No. 47-9) (“IOM Report”) (discussing the assessment of
epidemiologic, clinical, and biological evidence in regard to determining a causal relationship between vaccination
and injury, but not the assertions Dr. Tornatore stated regarding timeframe).
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Second Report
Dr. Tornatore’s Second Report endeavored specifically to defend GBS as the proper
diagnosis. Tornatore Second Rep. at 1–3. He noted that Petitioner’s September 2, 2015 EMG
results evidenced the presence of an acute inflammatory process of the proximal nerve roots. Ex.
9 at 48–49. Petitioner was also treated with five doses of IVIG immediately following her EMG
report—the standard of care for GBS. Ex. 7 at 171, 396–70. A follow-up EMG on April 6, 2016,
showed evidence of improvement, which was another indicator to Dr. Tornatore that Petitioner
had GBS (since it bulwarked both the effectiveness of the immunotherapy treatment plus the
monophasic course of her illness). Ex. 9 at 27.
Respondent’s expert, Dr. Timothy Vartanian, had disagreed with Dr. Tornatore’s
assessment that Petitioner had a recurrent autoimmune neuropathy, but Dr. Tornatore’s opinion
remained unchanged. Tornatore Second Rep. at 2–3. Dr. Tornatore noted, for example, her
discharge status on September 6, 2015, which expressed a “concern for a possible recurrence of
GBS,” and a note from Dr. Smith that when Petitioner was hospitalized the differential indicated
“recurrent GBS vs. CIDP.” Ex. 7 at 370; Ex. 9 at 39.
In regard to his medical theory, Dr. Tornatore pointed out that Dr. Vartanian did not dispute
the scientific mechanisms of molecular mimicry as a scientific principle, suggesting he concurred
that it was reputable. Dr. Tornatore Second Rep. at 4; Vartanian Rep. at 14. And although Dr.
Vartanian asserted there was a lack of epidemiologic data to support an association between GBS
and Tdap, Dr. Tornatore argued that epidemiology cannot rule out rare events such as vaccine
injuries. Tornatore Second Rep. at 4.
Finally, with regard to onset, Dr. Tornatore disagreed with Dr. Vartanian’s assessment that
the immune response could not result in a neurologic injury within 48 hours of vaccination.
Tornatore Second Rep. at 4. Rather, immediately after re-exposure to a foreign antigen, there is a
measurable increase in the immune response, thus making Petitioner’s onset of symptoms
medically acceptable. Id.
B. Respondent’s Expert – Timothy Vartanian, M.D., Ph.D.
Dr. Vartanian, a board-certified neurologist with subspecialties in caring for patients with
inflammatory demyelinating diseases, prepared one written report for Respondent in support of
the contention that there is not a casual association between the Tdap vaccine and GBS. Report,
dated September 30, 2021, filed as Ex. A (ECF No. 41-1) (“Vartanian Rep.”).
Dr. Vartanian received his bachelor’s degree from Oakland University, along with his
medical and doctorate degree from the University of Chicago. Curriculum Vitae, filed as Ex. B on
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November 8, 2021 (ECF No. 42-21) (“Vartanian CV”) at 1; Vartanian Rep. at 1. He completed a
residency at Massachusetts General Hospital in Neurology. Vartanian CV at 2; Vartanian Rep. at
1. He then completed two fellowships, the first at Beth Israel Hospital and the second at Harvard
Medical School. Vartanian CV at 2. Since 2009, Dr. Vartanian holds positions as a Professor at
Weill Cornell Medicine. and an attending neurologist at New York Presbyterian Hospital.
Vartanian CV at 2; Vartanian Rep. at 1. He has published a substantial number of peer-reviewed
articles. Vartanian CV at 11–23.
Like Dr. Tornatore, Dr. Vartanian engaged in a thorough review of Petitioner’s medical
history. Vartanian Rep. at 2–10. He noted that GBS is an acute inflammatory demyelinating
polyneuropathy typically triggered by an antecedent infection. Id. at 12. A classic clinical history
is that of an individual who suffers a common infection and then two weeks later begins to note
weakness in their distal lower limbs. Id.; P. van Doorn, Diagnosis, Treatment and Prognosis of
Guillain-Barré Syndrome (GBS), La Presse Médicale e193, e194 (2013), filed as Ex. A, Tab 17
(ECF No. 42-17) (“van Doorn”).
Dr. Vartanian agreed that Petitioner’s clinical presentation in 2005 was consistent with
GBS. Vartanian Rep. at 11. Testing of Petitioner’s CSF at that time showed acellularity and
elevated protein levels—hallmarks of GBS. Id.; Ex. 16 at 20. Her presentation was asymmetric,
and included an unusual finding with enhancement of the seventh and eighth nerve complex,
resulting in uncommon facial symptoms, but case report evidence showed this was possible. Ex. 9
at 27; T. Takazawa et al., Sudden Deafness and Facial Diplegia in Guillain-Barré Syndrome:
Radiological Depiction of Facial and Acoustic Nerve Lesions, 51 Internal Med. 2433, 2437 (2012),
filed as Ex. A, Tab 16 (ECF No. 42-16).
In 2015, Petitioner’s EMG/NCS also revealed characteristic findings associated with GBS.
Vartanian Rep. at 11; Ex. 9 at 48–49. Dr. Vartanian maintained, however, that subsequent testing
and the medical record did not establish evolution of her symptoms suggestive of new autoimmune
or inflammatory demyelination. Vartanian Rep. at 11; Ex. 9 at 48–49. Petitioner’s clinical course,
coupled with results of repeat EMGs, did not support the conclusion that Petitioner experienced a
recurrent autoimmune neuropathy characterized as GBS, although Dr. Vartanian did not elaborate
on what a correct diagnosis for her symptoms at this time might be. Vartanian Rep. at 11.
In addition, Dr. Vartanian maintained that there was an absence of a causal relationship
between the Tdap vaccine and GBS (independent of his questions about the proper diagnosis).
Vartanian Rep. at 14. He began with a discussion of molecular mimicry, which he allowed applies
to many examples of autoimmunity triggered by infection. Id. at 12–13. In essence (and specific
to demyelinating autoimmune illnesses like GBS), molecular mimicry occurs when a molecular
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motif found in an infectious or foreign agent10 resembles a similar motif present in the peripheral
nervous system myelin, raising the potential that antibodies generated against the foreign antigen
will mistakenly attack the peripheral myelin. Id. at 13.
However, Dr. Vartanian maintained, reliable literature11 did not support the contention that
the Tdap vaccine could instigate an autoimmune process mediated by molecular mimicry and lead
to GBS. See, e.g., Vartanian Rep. at 14–16; W. Yih et al., An Assessment of the Safety of Adolescent
and Adult Tetanus–Diphtheria–Acellular Pertussis (Tdap) Vaccine, Using Active Surveillance for
Adverse Events in the Vaccine Safety Datalink, 27 Vaccine 4257, 4261 (2009), filed as Ex. A, Tab
18 (ECF No. 42-8) (“Yih”) (“[w]e found no evidence of an association between Tdap and any of
the five predefined adverse events [including GBS] in a surveillance period that included 660,245
doses of Tdap over the course of 145 weeks”); J. Nelson et al., Adapting Group Sequential Methods
to Observational Postlicensure Vaccine Safety Surveillance: Results of a Pentavalent Combination
Dtap-IPV-Hib Vaccine Safety Study, 177 Am. J. Epidemiology 131, 131 (2013), filed as Ex. A,
Tab 13 (ECF No. 42-13) (“Nelson”) (“[n]o increased risk was detected among 149,337 DTaP-
IPV-Hib vaccinees versus historical comparators for any outcome, including . . . Guillain-Barré
syndrome . . . .”); J. Tuttle et al., The Risk of Guillain-Barre Syndrome After Tetanus-Toxoid-
Containing Vaccines in Adults And Children in The United States, 87 Am. J. Public Health 2045,
2045–47 (1997), filed as Ex. D (ECF No. 58-1) (concluding that if an association exists, it must
be extremely rare and not of public health significance); M. Daley et al., Safety of Diphtheria,
Tetanus, Acellular Pertussis and Inactivated Poliovirus (Dtap–IPV) Vaccine, 32 Vaccine 3019,
3019 (2014), filed as Ex. A, Tab 6 (ECF No. 42-6) (“Daley”) (“. . . there was no evidence of
increased risk for any of the pre-specified adverse events monitored.”); R. Baxter et al., Lack of
Association of Guillain-Barre Syndrome with Vaccinations, 57 Clinical Infection Diseases 197,
197 (2013), filed as Ex. A, Tab 1 (ECF No. 42-1) (“Baxter”) (finding no evidence of an increased
risk of GBS following vaccinations of any kind).
In addition, Dr. Vartanian maintained that Petitioner’s medical history was unsupportive
of the conclusion that the Tdap vaccine had caused her injury. Vartanian Rep at 11. He noted that
the etiology of Petitioner’s earlier GBS case in 2005 was mistakenly attributed to a vaccination
that the record did not corroborate as having occurred, while the notes contemporaneous with that
10 Most commonly in GBS, the infectious agent is bacterial, viral, or fungal. Vartanian Rep. at 14. Half the time an
antecedent infection is not reported nor is there recent vaccination, and in these cases, it is thought that subclinical
infection is driving autoimmunity. Id.
11 One piece of literature Dr. Vartanian referenced was an IOM Report, but it was not filed by Respondent (and as
noted earlier Petitioner did not cite to the accurate page numbers to support this assertion). However, some of
Respondent’s literature cites to IOM Reports, which (according to those authors) found the evidence inadequate to
accept or reject a causal relationship. S. Chang et al., U.S. Postlicensure Safety Surveillance for Adolescent and Adult
Tetanus, Diphtheria and Acellular Pertussis Vaccines: 2005–2007, 31 Vaccine 1447, 1450 (2013), filed as Ex. A, Tab
3 (ECF No. 42-3). Ultimately, the fact that the IOM report itself was not filed means I cannot give such contentions
much weight in my overall analysis.
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presentation acknowledged the possibility of multiple antecedent infections. Id.; Ex. 16 at 20.
Similar evidence of an antecedent infection was present in the record from her 2015 GBS incident.
Vartanian Rep. at 10 (citing a wound on her foot from a nail and reporting a subjective fever and
nausea). Dr. Vartanian also noted that antecedent gastrointestinal or respiratory infections are
widely understood by medical science to be closely associated with GBS, whereas the Tdap
vaccine has only anecdotal associations. Vartanian Rep. at 11; Baxter at 197. Thus, a prior
infection was the most likely explanation for both instances of Petitioner’s GBS. Id.
Dr. Vartanian’s opinion also included consideration of Petitioner’s onset and its
relationship to causation. Although the adaptive immune system can provide a quick response in
the event the body has previously encountered the same pathogen (or vaccine) previously, there is
still a limit to how quickly a memory response will result in an effective immune reaction.
Vartanian Rep. at 16–17. Here, the record established that Petitioner’s onset began one and a half
days after her vaccination, which Dr. Vartanian deemed too little time for humoral or cellular
immunity to cause an injury to the nervous system. Id.12
III. Procedural History
After the case’s initiation in August 2018, Petitioner filed medical records supporting the
claim, and then Respondent’s Rule 4(c) Report was filed on November 21, 2019 (ECF No. 22).
The case was assigned to me in January 2021. Expert reports were filed through January 2022.
Thereafter I set a schedule for a ruling on the record, and the parties acceded to this method of
resolution. The parties had fully briefed the matter by August 2022, and it is now ripe for
resolution.
IV. Parties’ Arguments
Petitioner argues that she was correctly diagnosed with a recurrent autoimmune neuropathy
(GBS) based on treater encounters. Mot. at 18–22; Reply at 2–3. Petitioner also maintains that she
has met the causation-in-fact burden based on the factors established by the Federal Circuit in
Althen v. Sec'y of Health & Hum. Servs., 418 F.3d 1274 (Fed. Cir. 2005); Mot. at 22–33; Reply at
3–9. Statements from Petitioner’s expert, she purports, support the contention that the Tdap
vaccine can cause GBS via molecular mimicry. Mot. at 25–26; Reply at 3–7. This determination
is also supported by prior Program decisions. See Mohamad v. Sec'y of Health & Hum. Servs., No.
16-1075V, 2022 WL 711604, *17–18 (Fed. Cl. Spec. Mstr. Jan. 27, 2022).
Ms. Dennington next claims that she has demonstrated a logical sequence of cause and
effect that the Tdap vaccine “did cause” her injury. Mot. at 27–31; Reply at 7–8. In support, she
notes that treating physicians allowed for the possibility that the vaccine was related to her injuries.
12 Dr. Vartanian also cited to a “Abolhassani 2020” article in support of this contention, but it was not filed.
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Mot. at 31. Petitioner and her mother also report that shortly before the onset of GBS symptoms
in 2005, Petitioner had received a tetanus vaccine and had a flu-like illness—not coincidental, in
Petitioner’s view, and demonstrated evidence of a rechallenge.13 Mot. at 27–29; Reply at 7. This
makes it likely that Petitioner experienced a quick onset of symptoms after her second vaccine
exposure because her immune system was previously primed with the tetanus toxoid antigen. Mot.
at 29–30; Reply at 8. Additionally, Petitioner observes that she presented with similar symptoms
in 2015 as she did in 2005. Mot. at 30–31. Finally, the timing of her onset—approximately 48
hours after receiving her Tdap vaccine—is medically-acceptable. Mot. 31–33; Reply at 8–9.
In opposing entitlement, Respondent questions the factual basis for the alleged injury,
maintaining that Ms. Dennington’s test results and medical records are not consistent with
recurrent GBS (or GBS generally for that matter). Opp. at 16–17. Additionally, Petitioner has not
preponderantly established a reliable medical theory causally connecting her vaccination to GBS.
Id. at 18. Petitioner relies on the theory of molecular mimicry too generally and does not support
such assertions with reliable literature specific to the Tdap vaccine. Id. at 18–19. Respondent also
cites to previous cases involving the Tdap vaccine and GBS, in which petitioners failed to produce
reliable scientific evidence to establish causation. See, e.g., Tompkins v. Sec'y of Health & Hum.
Servs., No. 10-261V, 2013 WL 3498652 (Fed. Cl. Spec. Mstr. June 21, 2013), mot. for review
den’d, 117 Fed. Cl. 713 (2014); Isaac v. Sec'y of Health & Hum. Servs., No. 08-601V, 2012 WL
3609993 (Fed. Cl. Spec. Mstr. July 30, 2012), mot. for review den’d, 108 Fed. Cl. 743 (2013),
aff’d, 540 F. App’x 999 (Fed. Cir. 2013). Respondent distinguishes these cases from Mohamad,
where Respondent effectively conceded Althen prong one (despite the special master not finding
the theory persuasive), and where the matter turned on literature not offered in this case. Opp. at
20; Mohamad, 2022 WL 711604, *17–18.
Under Althen prong two, Respondent argues, Petitioner’s reported onset occurred in the
context of an upper respiratory infection (along with other symptoms), which is more likely the
cause of her injury. Opp. at 21–22. Petitioner’s rechallenge argument is not supported by the
medical records as there was no indication of any vaccine received by Petitioner prior to the onset
of Petitioner’s symptoms in 2005. Id. at 21. And Petitioner’s showing under Althen prong three
also fails because it relies on evidence linking GBS and the 1976 H1N1 flu vaccine—a completely
different vaccine that does not contain any aluminum adjuvant. Id. at 24. Otherwise, onset would
be expected to occur within four days14 at the soonest, but Petitioner’s reported symptoms occurred
13 See generally Nussman v. Sec'y of Health & Hum. Servs., No. 99-500V, 2008 WL 449656, at *9 (Fed. Cl. Spec.
Mstr. Jan. 31, 2008), aff'd, 83 Fed. Cl. 111 (2008) (defining challenge-rechallenge as “when a person (1) is exposed
to one antigen, (2) reacts to that antigen in a particular way, (3) is given the same antigen again, and (4) reacts to that
antigen similarly”).
14 As noted earlier, Dr. Vartanian’s citation to “Abolhassani 2020” was referenced to support this timeframe, but this
literature was never filed.
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two days after vaccination, which does not fit with the current understanding of immunology and
neurology. Id.
V. Applicable Legal Standards
A. Petitioner’s Overall Burden in Vaccine Program Cases
To receive compensation in the Vaccine Program, a petitioner must prove either: (1) that
he suffered a “Table Injury”—i.e., an injury falling within the Vaccine Injury Table—
corresponding to one of the vaccinations in question within a statutorily prescribed period of time
or, in the alternative, (2) that his illnesses were actually caused by a vaccine (a “Non-Table
Injury”). See Sections 13(a)(1)(A), 11(c)(1), and 14(a), as amended by 42 C.F.R. § 100.3; §
11(c)(1)(C)(ii)(I); see also Moberly v. Sec’y of Health & Hum. Servs., 592 F.3d 1315, 1321 (Fed.
Cir. 2010); Capizzano v. Sec’y of Health & Hum. Servs., 440 F.3d 1317, 1320 (Fed. Cir. 2006).15
In this case, Petitioner does not assert a Table claim.
For both Table and Non-Table claims, Vaccine Program petitioners bear a “preponderance
of the evidence” burden of proof. Section 13(1)(a). That is, a petitioner must offer evidence that
leads the “trier of fact to believe that the existence of a fact is more probable than its nonexistence
before [he] may find in favor of the party who has the burden to persuade the judge of the fact’s
existence.” Moberly, 592 F.3d at 1322 n.2; see also Snowbank Enter. v. United States, 6 Cl. Ct.
476, 486 (1984) (mere conjecture or speculation is insufficient under a preponderance standard).
Proof of medical certainty is not required. Bunting v. Sec’y of Health & Hum. Servs., 931 F.2d
867, 873 (Fed. Cir. 1991). In particular, a petitioner must demonstrate that the vaccine was “not
only [the] but-for cause of the injury but also a substantial factor in bringing about the injury.”
Moberly, 592 F.3d at 1321 (quoting Shyface v. Sec’y of Health & Hum. Servs., 165 F.3d 1344,
1352–53 (Fed. Cir. 1999)); Pafford v. Sec’y of Health & Hum. Servs., 451 F.3d 1352, 1355 (Fed.
Cir. 2006). A petitioner may not receive a Vaccine Program award based solely on his assertions;
rather, the petition must be supported by either medical records or by the opinion of a competent
physician. Section 13(a)(1).
In attempting to establish entitlement to a Vaccine Program award of compensation for a
Non-Table claim, a petitioner must satisfy all three of the elements established by the Federal
Circuit in Althen, 418 F.3d at 1278: “(1) a medical theory causally connecting the vaccination and
the injury; (2) a logical sequence of cause and effect showing that the vaccination was the reason
for the injury; and (3) a showing of proximate temporal relationship between vaccination and
injury.”
15 Decisions of special masters (some of which I reference in this ruling) constitute persuasive but not binding
authority. Hanlon v. Sec’y of Health & Hum. Servs., 40 Fed. Cl. 625, 630 (1998). By contrast, Federal Circuit rulings
concerning legal issues are binding on special masters. Guillory v. Sec’y of Health & Hum. Servs., 59 Fed. Cl. 121,
124 (2003), aff’d 104 F. Appx. 712 (Fed. Cir. 2004); see also Spooner v. Sec’y of Health & Hum. Servs., No. 13-159V,
2014 WL 504728, at *7 n.12 (Fed. Cl. Spec. Mstr. Jan. 16, 2014).
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Each of the Althen prongs requires a different showing. Under Althen prong one, petitioners
must provide a “reputable medical theory,” demonstrating that the vaccine received can cause the
type of injury alleged. Pafford, 451 F.3d at 1355–56 (citations omitted). To satisfy this prong, a
petitioner’s theory must be based on a “sound and reliable medical or scientific explanation.”
Knudsen v. Sec’y of Health & Hum. Servs., 35 F.3d 543, 548 (Fed. Cir. 1994). Such a theory must
only be “legally probable, not medically or scientifically certain.” Id. at 549.
Petitioners may satisfy the first Althen prong without resort to medical literature,
epidemiological studies, demonstration of a specific mechanism, or a generally accepted medical
theory. Andreu v. Sec’y of Health & Hum. Servs., 569 F.3d 1367, 1378–79 (Fed. Cir. 2009) (citing
Capizzano, 440 F.3d at 1325–26). Special masters, despite their expertise, are not empowered by
statute to conclusively resolve what are essentially thorny scientific and medical questions, and
thus scientific evidence offered to establish Althen prong one is viewed “not through the lens of
the laboratorian, but instead from the vantage point of the Vaccine Act’s preponderant evidence
standard.” Id. at 1380. Accordingly, special masters must take care not to increase the burden
placed on petitioners in offering a scientific theory linking vaccine to injury. Contreras, 121 Fed.
Cl. at 245.
In discussing the evidentiary standard applicable to the first Althen prong, the Federal
Circuit has consistently rejected the contention that it can be satisfied merely by establishing the
proposed causal theory’s scientific or medical plausibility. See Boatmon v. Sec’y of Health & Hum.
Servs., 941 F.3d 1351, 1359 (Fed. Cir. 2019); see also LaLonde v. Sec’y of Health & Hum. Servs.,
746 F.3d 1334, 1339 (Fed. Cir. 2014) (“[h]owever, in the past we have made clear that simply
identifying a ‘plausible’ theory of causation is insufficient for a petitioner to meet her burden of
proof” (citing Moberly, 592 F.3d at 1322)); Howard v. Sec'y of Health & Hum. Servs., No. 16-
1592V, slip op. (Fed. Cl. Feb. 27, 2023) (affirming dismissal of a Tdap-CIDP case, and confirming
that “[t]he standard has been preponderance for nearly four decades”). Otherwise, petitioners always
have the ultimate burden of establishing their Vaccine Act claim with preponderant evidence. W.C.
v. Sec’y of Health & Hum. Servs., 704 F.3d 1352, 1356 (Fed. Cir. 2013) (citations omitted); Tarsell
v. United States, 133 Fed. Cl. 782, 793 (2017) (noting that Moberly “addresses the petitioner’s
overall burden of proving causation-in-fact under the Vaccine Act” by a preponderance standard).
The second Althen prong requires proof of a logical sequence of cause and effect, usually
supported by facts derived from a petitioner’s medical records. Althen, 418 F.3d at 1278; Andreu,
569 F.3d at 1375–77; Capizzano, 440 F.3d at 1326; Grant v. Sec’y of Health & Hum. Servs., 956
F.2d 1144, 1148 (Fed. Cir. 1992). In establishing that a vaccine “did cause” injury, the opinions
and views of the injured party’s treating physicians are entitled to some weight. Andreu, 569 F.3d
at 1367; Capizzano, 440 F.3d at 1326 (“medical records and medical opinion testimony are favored
in vaccine cases, as treating physicians are likely to be in the best position to determine whether a
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‘logical sequence of cause and effect show[s] that the vaccination was the reason for the injury’”)
(quoting Althen, 418 F.3d at 1280). Medical records are generally viewed as particularly
trustworthy evidence, since they are created contemporaneously with the treatment of the patient.
Cucuras v. Sec’y of Health & Hum. Servs., 993 F.2d 1525, 1528 (Fed. Cir. 1993).
Medical records and statements of a treating physician, however, do not per se bind the
special master to adopt the conclusions of such an individual, even if they must be considered and
carefully evaluated. Section 13(b)(1) (providing that “[a]ny such diagnosis, conclusion, judgment,
test result, report, or summary shall not be binding on the special master or court”); Snyder v. Sec’y
of Health & Hum. Servs., 88 Fed. Cl. 706, 746 n.67 (2009) (“there is nothing . . . that mandates
that the testimony of a treating physician is sacrosanct—that it must be accepted in its entirety and
cannot be rebutted”). As with expert testimony offered to establish a theory of causation, the
opinions or diagnoses of treating physicians are only as trustworthy as the reasonableness of their
suppositions or bases. The views of treating physicians should be weighed against other, contrary
evidence also present in the record—including conflicting opinions among such individuals.
Hibbard v. Sec’y of Health & Hum. Servs., 100 Fed. Cl. 742, 749 (2011) (not arbitrary or capricious
for special master to weigh competing treating physicians’ conclusions against each other), aff’d,
698 F.3d 1355 (Fed. Cir. 2012); Veryzer v. Sec’y of Dept. of Health & Hum. Servs., No. 06-522V,
2011 WL 1935813, at *17 (Fed. Cl. Spec. Mstr. Apr. 29, 2011), mot. for review denied, 100 Fed.
Cl. 344, 356 (2011), aff’d without opinion, 475 F. Appx. 765 (Fed. Cir. 2012).
The third Althen prong requires establishing a “proximate temporal relationship” between
the vaccination and the injury alleged. Althen, 418 F.3d at 1281. That term has been equated to the
phrase “medically-acceptable temporal relationship.” Id. A petitioner must offer “preponderant
proof that the onset of symptoms occurred within a timeframe which, given the medical
understanding of the disorder’s etiology, it is medically acceptable to infer causation.” de Bazan
v. Sec’y of Health & Hum. Servs., 539 F.3d 1347, 1352 (Fed. Cir. 2008). The explanation for what
is a medically acceptable timeframe must align with the theory of how the relevant vaccine can
cause an injury (Althen prong one’s requirement). Id. at 1352; Shapiro v. Sec’y of Health & Hum.
Servs., 101 Fed. Cl. 532, 542 (2011), recons. denied after remand, 105 Fed. Cl. 353 (2012), aff’d
mem., 503 F. Appx. 952 (Fed. Cir. 2013); Koehn v. Sec’y of Health & Hum. Servs., No. 11-355V,
2013 WL 3214877 (Fed. Cl. Spec. Mstr. May 30, 2013), mot. for rev. denied (Fed. Cl. Dec. 3,
2013), aff’d, 773 F.3d 1239 (Fed. Cir. 2014).
B. Legal Standards Governing Factual Determinations
The process for making determinations in Vaccine Program cases regarding factual issues
begins with consideration of the medical records. Section 11(c)(2). The special master is required
to consider “all [ ] relevant medical and scientific evidence contained in the record,” including
“any diagnosis, conclusion, medical judgment, or autopsy or coroner's report which is contained
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in the record regarding the nature, causation, and aggravation of the petitioner's illness, disability,
injury, condition, or death,” as well as the “results of any diagnostic or evaluative test which are
contained in the record and the summaries and conclusions.” Section 13(b)(1)(A). The special
master is then required to weigh the evidence presented, including contemporaneous medical
records and testimony. See Burns v. Sec'y of Health & Hum. Servs., 3 F.3d 415, 417 (Fed. Cir.
1993) (determining that it is within the special master's discretion to determine whether to afford
greater weight to contemporaneous medical records than to other evidence, such as oral testimony
surrounding the events in question that was given at a later date, provided that such determination
is evidenced by a rational determination).
As noted by the Federal Circuit, “[m]edical records, in general, warrant consideration as
trustworthy evidence.” Cucuras, 993 F.2d at 1528; Doe/70 v. Sec'y of Health & Hum. Servs., 95
Fed. Cl. 598, 608 (2010) (“[g]iven the inconsistencies between petitioner's testimony and his
contemporaneous medical records, the special master's decision to rely on petitioner's medical
records was rational and consistent with applicable law”), aff'd, Rickett v. Sec'y of Health & Hum.
Servs., 468 F. App’x 952 (Fed. Cir. 2011) (non-precedential opinion). A series of linked
propositions explains why such records deserve some weight: (i) sick people visit medical
professionals; (ii) sick people attempt to honestly report their health problems to those
professionals; and (iii) medical professionals record what they are told or observe when examining
their patients in as accurate a manner as possible, so that they are aware of enough relevant facts
to make appropriate treatment decisions. Sanchez v. Sec'y of Health & Hum. Servs., No. 11–685V,
2013 WL 1880825, at *2 (Fed. Cl. Spec. Mstr. Apr. 10, 2013); Cucuras v. Sec'y of Health & Hum.
Servs., 26 Cl. Ct. 537, 543 (1992), aff'd, 993 F.2d at 1525 (Fed. Cir. 1993) (“[i]t strains reason to
conclude that petitioners would fail to accurately report the onset of their daughter's symptoms”).
Accordingly, if the medical records are clear, consistent, and complete, then they should
be afforded substantial weight. Lowrie v. Sec'y of Health & Hum. Servs., No. 03–1585V, 2005 WL
6117475, at *20 (Fed. Cl. Spec. Mstr. Dec. 12, 2005). Indeed, contemporaneous medical records
are often found to be deserving of greater evidentiary weight than oral testimony—especially
where such testimony conflicts with the record evidence. Cucuras, 993 F.2d at 1528; see also
Murphy v. Sec'y of Health & Hum. Servs., 23 Cl. Ct. 726, 733 (1991), aff'd per curiam, 968 F.2d
1226 (Fed. Cir. 1992), cert. den'd, Murphy v. Sullivan, 506 U.S. 974 (1992) (citing United States
v. United States Gypsum Co., 333 U.S. 364, 396 (1947) (“[i]t has generally been held that oral
testimony which is in conflict with contemporaneous documents is entitled to little evidentiary
weight.”)).
However, the Federal Circuit has also noted that there is no formal “presumption” that
records are accurate or superior on their face to other forms of evidence. Kirby v. Sec’y of Health
& Hum. Servs., 997 F.3d 1378, 1383 (Fed. Cir. 2021). There are certainly situations in which
compelling oral or written testimony (provided in the form of an affidavit or declaration) may be
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more persuasive than written records, such as where records are deemed to be incomplete or
inaccurate. Campbell v. Sec'y of Health & Hum. Servs., 69 Fed. Cl. 775, 779 (2006) (“like any
norm based upon common sense and experience, this rule should not be treated as an absolute and
must yield where the factual predicates for its application are weak or lacking”); Lowrie, 2005 WL
6117475, at *19 (“[w]ritten records which are, themselves, inconsistent, should be accorded less
deference than those which are internally consistent”) (quoting Murphy, 23 Cl. Ct. at 733)).
Ultimately, a determination regarding a witness's credibility is needed when determining the
weight that such testimony should be afforded. Andreu, 569 F.3d at 1379; Bradley v. Sec'y of
Health & Hum. Servs., 991 F.2d 1570, 1575 (Fed. Cir. 1993).
When witness testimony is offered to overcome the presumption of accuracy afforded to
contemporaneous medical records, such testimony must be “consistent, clear, cogent, and
compelling.” Sanchez, 2013 WL 1880825, at *3 (citing Blutstein v. Sec'y of Health & Hum. Servs.,
No. 90–2808V, 1998 WL 408611, at *5 (Fed. Cl. Spec. Mstr. June 30, 1998)). In determining the
accuracy and completeness of medical records, the Court of Federal Claims has listed four possible
explanations for inconsistencies between contemporaneously created medical records and later
testimony: (1) a person's failure to recount to the medical professional everything that happened
during the relevant time period; (2) the medical professional's failure to document everything
reported to her or him; (3) a person's faulty recollection of the events when presenting testimony;
or (4) a person's purposeful recounting of symptoms that did not exist. La Londe v. Sec'y of Health
& Hum. Servs., 110 Fed. Cl. 184, 203–04 (2013), aff'd, 746 F.3d 1334 (Fed. Cir. 2014). In making
a determination regarding whether to afford greater weight to contemporaneous medical records
or other evidence, such as testimony at hearing, there must be evidence that this decision was the
result of a rational determination. Burns, 3 F.3d at 417.
C. Analysis of Expert Testimony
Establishing a sound and reliable medical theory often requires a petitioner to present
expert testimony in support of his claim. Lampe v. Sec’y of Health & Hum. Servs., 219 F.3d 1357,
1361 (Fed. Cir. 2000). Vaccine Program expert testimony is usually evaluated according to the
factors for analyzing scientific reliability set forth in Daubert v. Merrell Dow Pharm., Inc., 509
U.S. 579, 594–96 (1993). See Cedillo v. Sec’y of Health & Hum. Servs., 617 F.3d 1328, 1339 (Fed.
Cir. 2010) (citing Terran v. Sec’y of Health & Hum. Servs., 195 F.3d 1302, 1316 (Fed. Cir. 1999).
Under Daubert, the factors for analyzing the reliability of testimony are:
(1) whether a theory or technique can be (and has been) tested; (2) whether the
theory or technique has been subjected to peer review and publication; (3) whether
there is a known or potential rate of error and whether there are standards for
controlling the error; and (4) whether the theory or technique enjoys general
acceptance within a relevant scientific community.
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Terran, 195 F.3d at 1316 n.2 (citing Daubert, 509 U.S. at 592–95).
In the Vaccine Program the Daubert factors play a slightly different role than they do when
applied in other federal judicial settings, like the district courts. Typically, Daubert factors are
employed by judges (in the performance of their evidentiary gatekeeper roles) to exclude evidence
that is unreliable or could confuse a jury. By contrast, in Vaccine Program cases these factors are
used in the weighing of the reliability of scientific evidence proffered. Davis v. Sec'y of Health &
Hum. Servs., 94 Fed. Cl. 53, 66–67 (2010) (“uniquely in this Circuit, the Daubert factors have
been employed also as an acceptable evidentiary-gauging tool with respect to persuasiveness of
expert testimony already admitted”). The flexible use of the Daubert factors to evaluate the
persuasiveness and reliability of expert testimony has routinely been upheld. See, e.g., Snyder, 88
Fed. Cl. at 742–45. In this matter (as in numerous other Vaccine Program cases), Daubert has not
been employed at the threshold, to determine what evidence should be admitted, but instead to
determine whether expert testimony offered is reliable and/or persuasive.
Respondent frequently offers one or more experts in order to rebut a petitioner’s case.
Where both sides offer expert testimony, a special master's decision may be “based on the
credibility of the experts and the relative persuasiveness of their competing theories.”
Broekelschen v. Sec'y of Health & Hum. Servs., 618 F.3d 1339, 1347 (Fed. Cir. 2010) (citing
Lampe, 219 F.3d at 1362). However, nothing requires the acceptance of an expert's conclusion
“connected to existing data only by the ipse dixit of the expert,” especially if “there is simply too
great an analytical gap between the data and the opinion proffered.” Snyder, 88 Fed. Cl. at 743
(quoting Gen. Elec. Co. v. Joiner, 522 U.S. 146 (1997)); see also Isaac v. Sec'y of Health & Hum.
Servs., No. 08–601V, 2012 WL 3609993, at *17 (Fed. Cl. Spec. Mstr. July 30, 2012), mot. for
review den'd, 108 Fed. Cl. 743 (2013), aff'd, 540 F. App’x. 999 (Fed. Cir. 2013) (citing Cedillo,
617 F.3d at 1339). Weighing the relative persuasiveness of competing expert testimony, based on
a particular expert's credibility, is part of the overall reliability analysis to which special masters
must subject expert testimony in Vaccine Program cases. Moberly, 592 F.3d at 1325–26
(“[a]ssessments as to the reliability of expert testimony often turn on credibility determinations”);
see also Porter v. Sec'y of Health & Hum. Servs., 663 F.3d 1242, 1250 (Fed. Cir. 2011) (“this court
has unambiguously explained that special masters are expected to consider the credibility of expert
witnesses in evaluating petitions for compensation under the Vaccine Act”).
D. Consideration of Medical Literature
Both parties filed numerous items of medical and scientific literature in this case, but not
all such items factor into the outcome of this decision. While I have reviewed all the medical
literature submitted in this case, I discuss only those articles that are most relevant to my
determination and/or are central to Petitioner’s case—just as I have not exhaustively discussed
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every individual medical record filed. Moriarty v. Sec’y of Health & Hum. Servs., No. 2015–5072,
2016 WL 1358616, at *5 (Fed. Cir. Apr. 6, 2016) (“[w]e generally presume that a special master
considered the relevant record evidence even though he does not explicitly reference such evidence
in his decision”) (citation omitted); see also Paterek v. Sec’y of Health & Hum. Servs., 527 F.
App’x 875, 884 (Fed. Cir. 2013) (“[f]inding certain information not relevant does not lead to—
and likely undermines—the conclusion that it was not considered”).
E. Standards for Ruling on the Record
I am resolving Petitioner’s claim on the filed record, and the parties have not challenged
my determination to do so. Mot. at 1; Opp. at 1. The Vaccine Act and Rules not only contemplate
but encourage special masters to decide petitions on the papers where (in the exercise of their
discretion) they conclude that doing so will properly and fairly resolve the case. Section
12(d)(2)(D); Vaccine Rule 8(d). The decision to rule on the record in lieu of hearing has been
affirmed on appeal. Kreizenbeck v. Sec’y of Health & Hum. Servs., 945 F.3d 1362, 1366 (Fed. Cir.
2020); see also Hooker v. Sec’y of Health & Hum. Servs., No. 02-472V, 2016 WL 3456435, at *21
n.19 (Fed. Cl. Spec. Mstr. May 19, 2016) (citing numerous cases where special masters decided
case on the papers in lieu of hearing and that decision was upheld). I am simply not required to
hold a hearing in every matter, no matter the preferences of the parties. Hovey v. Sec’y of Health
& Hum. Servs., 38 Fed. Cl. 397, 402–03 (1997) (determining that special master acted within his
discretion in denying evidentiary hearing); Burns, 3 F.3d at 417; Murphy v. Sec’y of Health &
Hum. Servs., No. 90-882V, 1991 WL 71500, at *2 (Fed. Cl. Spec. Mstr. Apr. 19, 1991).
ANALYSIS
I. An Overview of Relevant Medical Terms and Applicable Prior Decisions
GBS has been defined as an acute, monophasic peripheral neuropathy involving rapidly
progressive and ascending motor neuron paralysis, which is thought to have an autoimmune
mechanism. Fokke at 34. Increased protein levels in the cerebral spinal fluid without a
corresponding increase in cells is often featured in GBS. Id. Its characteristics typically include
generalized muscle weakness combined with sensory symptoms. van Doorn at e195. GBS has an
acute onset, is monophasic, and is not steroid-responsive. Id. at e198.
There is a large body of reasoned decisions16 affirming the existence of an association
between the flu vaccine and peripheral neuropathies—most often GBS. Indeed, GBS occurring
after receipt of a flu vaccine is the basis for a Table claim. 42 C.F.R. § 100.3.14. This means the
Government has agreed that sufficiently-probative and reliable science on the topic existed to
16 Although prior decisions from different cases do not control the outcome herein, special masters may reasonably
take into account, for guidance, the logic of reasoned entitlement determinations. In fact, it is wise to do so, given how
often similar causation theories or fact patterns arise in Vaccine Program cases.
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justify conceding causation, at least for Program purposes. Haskins v. Secretary of Health & Hum.
Servs., No. 18-1776, 2020 WL 1870279 (Fed. Cl. Spec. Mstr. Mar. 13, 2019). Indeed, even in
cases where a Table element for a flu vaccine-GBS claim cannot be met (for example, when onset
is too short or long to fit within the timeframe of 3-42 days set for the claim), any subsequent
causation-in-fact analysis does not usually turn on the “can cause” first Althen prong. See Welch
v. Sec'y of Health & Hum. Servs., No. 18-494V, 2019 WL 349360 (Fed. Cl. Spec. Mstr. July 2,
2019).
Other vaccines have also been found causal of GBS, although there is disagreement among
the special masters as to the preponderant strength of these associations. See, e.g., Gross v. Sec'y
of Health & Hum. Servs., No. 17-1075V, 2022 WL 9669651, at *36–37 (Fed. Cl. Spec. Mstr. Sept.
22, 2022) (showing the pneumococcal vaccine caused GBS); but see Trollinger v. Sec'y of Health
& Hum. Servs., No. 16-473V, 2023 WL 2521912, at *30 (Fed. Cl. Spec. Mstr. Feb. 17, 2023),
appeal docketed, No. 16-473V, (Fed. Cl. Mar. 17, 2023) (finding that the pneumococcal vaccine
was not shown to cause GBS); Bielak v. Sec'y of Health & Hum. Servs., No. 18-761V, 2022 WL
18058244, at *34 (Fed. Cl. Spec. Mstr. Dec. 9, 2022) (same). It thus cannot be said that the
Program has developed a consistent view as to what the science preponderantly “says” about
causation when the flu vaccine is not involved. Instead, it appears that the outcome in such cases
is mostly a function of the evidence before the special master with no clear trend one way or the
other.
This is definitely true in the context of claims that the Tdap vaccine can cause GBS. Several
cases decided in the past ten years found no causal association between the two. See, e.g., Winkler
v. Sec'y of Health & Hum. Servs., No. 18-203V, 2021 WL 6276203 (Fed. Cl. Spec. Mstr. Dec. 10,
2021), mot. for review den’d, 2022 WL 1528779 (2022); Montgomery v. Sec'y of Health & Hum.
Servs., No. 15-1037V, 2019 WL 2511352 (Fed. Cl. Spec. Mstr. May 21, 2019); Tompkins, 2013
WL 3498652; Isaac, 2012 WL 3609993.17
In Isaac, for example, the petitioner offered molecular mimicry as her causal theory. Isaac,
2012 WL 3609993, at *6. But the special master determined that Dr. Tornatore (who also served
as that petitioner’s expert) had over-relied on a case report18 and there was an absence of focus on
molecular mimicry as a theory of vaccine injury—an allegation also made by Respondent in this
case. Id. at *20–21. This determination was affirmed on appeal at the Court of Federal Claims and
Federal Circuit. In Tompkins, the special master denied entitlement in a case alleging that a number
17 I have also decided a few cases finding no causal association between the Tdap vaccine and CIDP—albeit a different
injury from GBS. See, e.g., Howard v. Sec'y of Health & Hum. Servs., No. 16-1592V, 2022 WL 4869354 (Fed. Cl.
Spec. Mstr. Aug. 31, 2022), mot. for review den’d, slip op. (Fed. Cl. Feb. 27, 2023); Sanchez v. Sec'y of Health &
Hum. Servs., No. 18-1012V, 2022 WL 1013264, at *1 (Fed. Cl. Spec. Mstr. Mar. 11, 2022).
18 The case report in Isaac was also briefly referred to in this case. See J.D. Pollard & G. Selby, Relapsing Neuropathy
Due to Tetanus Toxoid, 37 J. Neurol. Sci. 113 (1978), filed as Ex. 43 (ECF No. 42-5).
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of vaccines received at the same time, including the Tdap vaccine, caused a petitioner's GBS, but
the causal theory put forward attempted to assert that the vaccines could also individually trigger
the disease. Tompkins, 2013 WL 3498652, at *15. The petitioner's expert, however, relied heavily
on VAERS passive surveillance data,19 and otherwise invoked a number of theories (molecular
mimicry, or endotoxin in tetanus-containing vaccines) that were only cursorily discussed. Id. at
*19–23.
Several cases go the other way, as Petitioner notes. In Mohamad, a special master ruled in
the petitioner's favor in a Tdap-GBS case, but almost wholly based on determination that the
Government had conceded the first Althen prong, while also emphasizing evidence of prior post-
vaccination demyelination, suggesting proof of “rechallenge.” See Mohamad v. Sec'y of Health &
Hum. Servs., No. 16-1075V, 2022 WL 711604, at *18 n.17 (Fed. Cl. Spec. Mstr. Jan. 27, 2022);
see also Swaiss v. Sec'y of Health & Hum. Servs., No. 15-286V, 2019 WL 6520791, at *23-27
(Fed. Cl. Spec. Mstr. Nov. 4, 2019) (determining a small fiber neuropathy (characterized in Swaiss
as “a variant” of GBS) could be caused by the Tdap vaccine via the mechanism of molecular
mimicry, but acknowledging that the evidence offered to associate GBS and Tdap generally was
somewhat lacking). Most recently, a special master granted entitlement, but heavily focused on a
discussion of certain reports issued by the Institute of Medicine (some of which were not filed
here), and only briefly analyzed petitioner’s theory, which relied on theories other than molecular
mimicry. Harris v. Sec'y of Health & Hum. Servs., No. 18-944V, slip op. (Fed. Cl. Spec. Mstr.
Feb. 21, 2023).
Thus, it certainly cannot be said that claims relying on the Tdap vaccine’s association with
GBS are categorically ruled out—even if it is also clear, at the threshold, that there is a meaningful
decline in the amount of reliable scientific evidence associating that vaccine to this kind of nerve
injury, when compared to what is known about GBS and the flu vaccine—and reason therefore to
doubt that any putative association is well-founded.
II. Petitioner Has Preponderantly Established Her GBS Diagnosis
It is often appropriate for a special master to first determine which alleged injury is best
supported by the evidence before applying the Althen test—particularly when the injury is
19 The Vaccine Adverse Event Reporting System (“VAERS”) is a national warning system designed to detect safety
problems in U.S.-licensed vaccines. See About VAERS, VAERS, https://vaers hhs.gov/abouthtml (last visited Mar.
23, 2023). It is managed by both the CDC and the FDA. VAERS monitors and analyzes reports of vaccine related
injuries and side effects from both healthcare professionals and individuals. But it has been observed in the Program
that VAERS data is not particularly probative of causation unless supplemented with other reliable evidence—since
a VAERS report only establishes a temporal, post-vaccination occurrence, and thus shines no light on the possibility
of causation itself. See also Vig v. Sec'y of Health & Human Servs., No. 01–198V, 2013 WL 6596683, at *17 (Fed.
Cl. Spec. Mstr. Nov. 14, 2013) (“VAERS is a stocked pond, containing only reports of adverse events after
vaccinations but no data about the number of vaccines administered or the occurrence of the same adverse event in
individuals who have not been vaccinated”).
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disputed—so that “the special master could subsequently determine causation relative to the
injury.” Broekelschen, 618 F.3d at 1346. In some cases, determining the injury obviates entirely
the need for any Althen analysis, since the petitioner’s claim, and causation theory, is dependent
on a finding of a specific injury. Id.
In this case, the parties dispute the proper diagnosis. Opp. at 16–17. The record best
supports Petitioner’s contention, however. First, there is ample, trustworthy treater support for
Petitioner’s preferred diagnosis. Petitioner’s treating neurologist, Dr. Smith, diagnosed Petitioner
with GBS on numerous occasions. Ex. 7 at 136–37, 140–41, 150. Although Dr. Smith later
included CIDP in his differential diagnosis in December 2015 (Ex. 9 at 37–39), he clarified a year
later his view that Petitioner did not have “ongoing CIDP,” since she had not displayed new active
lesions, and was symptomatically stable (evidence of distal demyelination was residual in nature).
Ex. 9 at 3, 30, 34. Although I am never bound to accept a treater’s opinion, I may give weight to
their views. Snyder, 88 Fed. Cl. at 746 n.67. Here, Petitioner consistently saw Dr. Smith, and he
reached conclusions that seem reasonable based upon the records in which they are set forth.
Second, the medical records largely appear consistent with the conclusion that Petitioner
was suffering from GBS. Petitioner underwent complete diagnostic workups, including labs,
MRIs, a lumbar puncture, and EMG/NCS tests. This is the evidence upon which Dr. Smith relied.
Dr. Tornatore also persuasively established that Petitioner presented with defining features of
GBS—not CIDP. The latter diagnosis has ultimately limited support in the record, even if (due
mostly to the recurrent aspect of Petitioner’s GBS, especially since she experienced two separate
instances of it over several years) CIDP was reasonably raised as a possibility.
Dr. Vartanian makes a number of points in opposition (citing to Petitioner’s test results),
but does not offer a more specific diagnostic view. He opined that results of Petitioner’s EMG
results showed evidence of her prior bout of GBS in 2005. However, Dr. Vartanian did not explain
how such residual evidence would be revealed in Petitioner’s test results ten years later. Dr.
Vartanian otherwise did not fully substantiate his argument, and provided a lackluster explanation
for why Petitioner did not have GBS despite her treaters and Dr. Tornatore, who more persuasively
supported the diagnosis with record references. At bottom, the overall record preponderates in
Petitioner’s favor on diagnosis.
III. Petitioner Has not Carried Her Burden of Proof20
A. Althen Prong One
Petitioner has not established that the Tdap vaccine could cause GBS with sufficient
reliable scientific or medical evidence. This does not mean that some of her causation contentions
20
I address the three prongs in order of their importance to my decision.
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lacked trustworthy or reliable support. The core concept of molecular mimicry is a reliable theory
for how some autoimmune diseases occur, and it has in other contexts been persuasively connected
to vaccination, which due to antigenic similarity between a vaccine component and self structure,
could result in an autoimmune cross-attack.
However, I have now repeatedly observed in Program cases that more must be done to
preponderantly establish causation than simply “raise the flag” of molecular mimicry as a
generally-reliable concept. See, e.g., McKown v. Sec'y of Health & Hum. Servs., No. 15-1451V,
2019 WL 4072113, at *50 (Fed. Cl. Spec. Mstr. July 15, 2019) (citing Devonshire v. Sec'y of
Health & Hum. Servs., No. 99-031V, 2006 WL 2970418, at *15 (Fed. Cl. Spec. Mstr. Sept. 2006))
(“[b]ut merely chanting the magic words ‘molecular mimicry’ in a Vaccine Act case does not
render a causation theory scientifically reliable, absent additional evidence specifically tying the
mechanism to the injury and/or vaccine in question”) (emphasis in original), mot. for review den’d,
76 Fed. Cl. 452 (2007)). Instead, claimants and their experts must provide sufficient connective
evidence to allow a conclusion that it is “more likely than not” the specific vaccine in question that
could cause the relevant injury.
Dr. Tornatore was well qualified to offer the opinion he did, but he did not attempt to
establish the kind of homology between vaccine antigens and self structures in the nerves that is a
common starting point for molecular mimicry when offered as a mechanistic explanation. He also
pointed to no specific antibody created in response to the Tdap vaccine that might cross-react
against nerve myelin in the manner GBS is believed to progress. Rather, he unpersuasively argued
that because Dr. Vartanian did not dispute the scientific principles behind molecular mimicry,
Respondent had effectively conceded the existence of a causal relationship between the Tdap
vaccine and GBS. Tornatore Second Rep. at 14. But as noted above, molecular mimicry’s
reliability per se does not mean it explains how every covered vaccine could cause any
autoimmune condition.
Dr. Tornatore also relied on case reports regarding peripheral neuropathies following other
vaccinations to prove his theory. But it is well established that case report evidence is only weakly
probative of causation. See, e.g., Pearson v. Sec’y of Health & Human Servs., No. 17-489V, 2019
WL 1150044, at *11 (Fed. Cl. Spec. Mstr. Feb. 7, 2019) (concluding that case reports receive only
limited evidentiary weight and cannot cure Althen prong one deficiencies); Harris v. Sec’y of
Health & Human Servs., No. 10-322V, 2014 WL 3159377, at *18 (Fed. Cl. Spec. Mstr. June 10,
2014) (“case reports are generally not a valuable form of evidence”). And those Petitioner offered
were not specific to the Tdap vaccine, further diminishing their evidentiary value. See, e.g., Shaw
at 344–50; Khamaisi at 768–79.
Dr. Vartanian, by contrast, offered a more persuasive argument on the causation side of the
case than with respect to his diagnostic opinion. In particular, he referenced several pieces of
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reliable literature which did not observe an association between the Tdap vaccine and injury. See,
e.g., Yih at 4261; Nelson at 131; Daley at 3019. While it is almost a bromide in Program cases that
epidemiologic studies are never a required kind of proof that claimants must offer to meet their
burden, they can be considered when they exist—and given weight if they are reliable and do not
support causation, as here. King v. Sec'y of Health & Hum. Servs., No. 03-584V, 2010 WL 892296,
at *74 (Fed. Cl. Spec. Mstr. Mar. 12, 2010) (“[c]onsistent with the teachings of Daubert, Terran,
and Grant, special masters have routinely found that epidemiologic evidence, and/or other medical
journal articles, while not dispositive, should be considered in evaluating scientific theories.”).
This is not the first case in which a petitioner has unsuccessfully attempted to argue that
the Tdap vaccine can cause GBS. While prior determinations do not determine the outcome, in the
end I see no evidence offered herein more persuasive on this question than what I have previously
considered. Even if it remains debatable whether this vaccine can have the same pathologic impact
as evidence indicates the flu vaccine does, Petitioner’s showing in this case is insufficient for me
to find this Althen prong was satisfied.
B. Althen Prong Three
The experts agreed that Petitioner experienced onset occurring within 48 hours of
vaccination, but disputed whether this timeframe was medically acceptable. Dr. Vartanian argued
that the adaptive immune response cannot respond so quickly, whereas Dr. Tornatore found that
an even more rapid response was acceptable (assuming that Petitioner had experienced rechallenge
to the Tdap vaccine).
After review of the evidence, I deem Respondent’s position more persuasive. An
autoimmune cross-reaction with molecular mimicry as its mechanism would rely on an adaptive
response (in which the immune system must first “see” the presenting antigen in the vaccine, then
generate antibodies that can lead the attack on self nerve tissues)21 that would not have run its
course within two days such that symptoms of the demyelinating damage central to GBS would
manifest. Such a short timeframe is simply too quick, as I have found in comparable cases. See,
e.g., Rowan v. Sec'y of Health & Hum. Servs., No. 17-760V, 2020 WL 2954954, at *17 (Fed. Cl.
Spec. Mstr. Apr. 28, 2020) (36-hour onset for GBS after receipt of flu vaccine not medically
acceptable).22
21 I have previously described in detail how there is a “lag and log” phase in the adaptive immune response—“[l]ag
begins the process and is the time during which the body encounters foreign antigens and through recognition of them
initiates an adaptive process, while log is the phase when those antibodies are actually produced.” Rowan v. Sec'y of
Health & Hum. Servs., No. 17-760V, 2020 WL 2954954, at *17 (Fed. Cl. Spec. Mstr. Apr. 28, 2020) (citing Forrest
v. Sec'y of Health & Human Servs., No. 14-1016V, 2019 WL 925495, at *6 (Fed. Cl. Spec. Mstr. Jan. 28, 2019)).
22 I also note that the flu vaccine-GBS Table claim only concedes causation for GBS onsets occurring no sooner than
three days post-vaccination. 42 C.F.R. § 100.3(a)(XIV)(D). Thus, even putting aside the Althen prong one deficiencies
of this case, timing of Ms. Dennington’s onset would remain problematic, as it was in cases like Rowan.
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To evade this timeframe deficiency, Petitioner relied a bit on the concept of an immune
memory response to the vaccine, based on the contention (uncorroborated by record proof) that
Petitioner and/or her mother recalled her receiving a Tdap dose not long before her onset of 2005
GBS, thus establishing a “rechallenge” context (in which immune memory would result in a faster
response). See, e.g., Mot. at 27–29. But even if this vaccination event did occur, Dr. Vartanian
persuasively established that a shorter response would still take more than two days to generate
the relevant antibodies. In reaction, Dr. Tornatore attempted to substantiate his timing arguments
by relying on Schonberger, an item of literature involving only to the flu vaccine, and one that is
now more than 40 years old. Schonberger at 105. Nothing was offered by Petitioner on timing
specific to the Tdap vaccine, and Petitioner’s case reports discussing another vaccine’s (Hep. B)
GBS association in fact documented a longer onset timeframe than herein. See, e.g., Shaw at 342
(documenting GBS cases occurring within seven weeks of the most proximate vaccine dose);
Khamaisi at 767 (reporting that an individual developed GBS ten weeks after vaccination).
C. Althen Prong Two
There is treater support in Petitioner’s medical records for a vaccine causal relationship,
supportive of the “did cause” Althen prong. But I am not bound to accept a treater’s opinion.
Snyder, 88 Fed. Cl. at 746 n.67. Rather, I may weigh the basis for such a view, and need not take
it at face value simply because it was rendered contemporaneously.
Here, it appears in several instances that treaters made this reference on the basis of
representations by Petitioner or her mother that she had previously incurred post-vaccination GBS.
See Ex. 8 at 3 (“per mom [patient] was seen at TCH in 2005 with same complaints”). But as even
Petitioner admits, her 2005 records do not establish that she received the Tdap vaccine in 2005.
Mot. at 28. Indeed, the records do not even document the “same” symptoms. In 2005, Petitioner
reported that her symptoms began with a fever, headache, and neck pain before developing facial
tingling and difficulty walking, whereas Petitioner’s symptoms in 2015 began in the context of
mild pain and chills due to a wound on her foot and a two-day history of a subjective fever and
nausea, which later progressed to numbness and tingling in her lower extremities. Ex. 6 at 11, 29;
Ex. 8 at 3; Ex. 16 at 2. I thus do not find that the relevant treater views of causality were reasoned,
since they assumed a prior vaccine relationship when that underlying vaccination event cannot be
substantiated.
Contentions about the “second” dose of Tdap vaccine constituting an immune rechallenge
are also unavailing. Ex. 7 at 140, 154; Ex. 9 at 39. Dr. Tornatore’s arguments about a shorter
immune memory response (which in turn would allow for a shorter post-vaccination onset) relied
on the accuracy of assertions that Petitioner received the vaccine in 2005, but the record does not
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substantiate that allegation. And as noted above, I otherwise determine that even in the context of
a rechallenge, onset would likely take more than two days.
Finally, I observe evidence in the record of a potential alternative explanation for her GBS
that was not adequately explained by Petitioner.23 It was noted that Petitioner’s 2015 Tdap
vaccination was due to a rash and abscess from an “old rusty pole,” which could have caused an
intercurrent infection. Ex. 6 at 29. Even Petitioner’s own expert noted that foreign antigens like
viral or bacterial infections can result in the activation of the immune system, and in rare cases
cause the body to target its own nervous system. Tornatore First Rep. at 21–22. While I cannot
conclude there was an alternative cause for her GBS, this evidence certainly undermines any
contention that nothing else could explain it, especially since (as Dr. Vartanian maintained)
evidence of antecedent infections causing GBS is much stronger than what links GBS to vaccines.
CONCLUSION
A Program entitlement award is only appropriate for claims supported by preponderant
evidence. Here, Petitioner has not made such a showing. Petitioner is therefore not entitled to
compensation.
In the absence of a motion for review filed pursuant to RCFC Appendix B, the Clerk of the
Court SHALL ENTER JUDGMENT in accordance with the terms of this Decision.24
IT IS SO ORDERED.
/s/ Brian H. Corcoran
Brian H. Corcoran
Chief Special Master
23 Even though petitioners are never burdened with disproving an alternative cause in their primary case, they may not
ignore alternative evidence undermining their Althen showing. See Snyder v. Sec'y of Health & Hum. Servs., 553 F.
App'x 994, 1000 (Fed. Cir. 2014) (“no evidence should be embargoed from the special master’s consideration simply
because it is also relevant to another inquiry under the statute”) (quoting Stone v. Sec'y of Health & Hum. Servs., 676
F.3d 1373, 1380 (Fed. Cir. 2012); see also de Bazan, 539 F.3d at 1353 (“[t]he government, like any defendant, is
permitted to offer evidence to demonstrate the inadequacy of the petitioner’s evidence on a requisite element of the
petitioner’s case-in-chief”). Thus, I consider this proof in weighing Petitioner’s “did cause” success—although I do
not give it substantial weight.
24 Pursuant to Vaccine Rule 11(a), the parties may expedite entry of judgment if (jointly or separately) they file notices
renouncing their right to seek review.
28

================================================================================
DOCUMENT 2: USCOURTS-cofc-1_18-vv-01303-1
Date issued/filed: 2023-10-06
Pages: 16
Docket text: PUBLIC DECISION (Originally filed 9/20/2023) regarding 66 Order on Motion for Review, JUDGE VACCINE ORDER/OPINION, 59 DECISION of Special Master. Signed by Judge Zachary N. Somers. (mss) Service on parties made.
--------------------------------------------------------------------------------
Case 1:18-vv-01303-ZNS Document 68 Filed 10/06/23 Page 1 of 16
In the United States Court of Federal Claims
No. 18-1303V
(Filed Under Seal: September 20, 2023)∗
(Reissued: October 6, 2023)
* * * * * * * * * * * * * * * * * * *
*
TARA DENNINGTON, *
*
Petitioner, *
*
v. *
*
SECRETARY OF HEALTH *
AND HUMAN SERVICES, *
*
Respondent. *
*
* * * * * * * * * * * * * * * * * * *
Michael P. Milmoe, argued the motion for review, Leah VaSahnja Durant, counsel of
record, Law Offices of Leah V. Durant, PLLC, of Washington, D.C., for Petitioner.
Tyler King, Trial Attorney, Torts Branch, Civil Division, U.S. Department of Justice, of
Washington, D.C., for Respondent.
OPINION AND ORDER
SOMERS, Judge.
Before the Court is a motion for review of the Chief Special Master’s decision denying
compensation under the National Vaccine Injury Compensation Program, filed by Petitioner,
Tara Dennington (“Petitioner”). See ECF Nos. 61, 62. The Secretary of Health and Human
Services (“Respondent”) filed a response to Petitioner’s motion, see ECF No. 64 (“Response”),
and the Court held oral argument on July 27, 2023.
In her motion for review, Petitioner seeks compensation pursuant to the National
Childhood Vaccine Injury Act of 1986 (“Vaccine Act”), 42 U.S.C. §§ 300aa–10 to 34,
contending that a tetanus, diphtheria, and acellular pertussis (“Tdap”) vaccine caused her to
develop Guillain-Barré syndrome (“GBS”). The Chief Special Master denied Petitioner’s claim,
∗ On September 20, 2023, the Court issued this opinion and order under seal in accordance with
Rule 18(b) of the Vaccine Rules (Appendix B) of the U.S. Court of Federal Claims. The Court provided
the parties 14 days to proposed redactions. The parties did not propose any redactions, and, accordingly,
the Court reissues this opinion and order in its original form.

Case 1:18-vv-01303-ZNS Document 68 Filed 10/06/23 Page 2 of 16
concluding that: (1) Petitioner did not preponderantly establish that the Tdap vaccine she
received could cause GBS, or (2) that it did so in a medically acceptable timeframe. Petitioner
now seeks review of that decision. For the reasons provided below, the Court finds that
Petitioner has not met the high burden imposed under the Vaccine Act to set aside a special
master’s decision and, therefore, denies Petitioner’s motion for review.
BACKGROUND
A. Factual History
Petitioner has suffered from bouts of GBS, both as a child and as an adult. She alleges
that she incurred the bout of GBS at issue here from a Tdap vaccine she received on August 30,
2015. The Chief Special Master’s Entitlement Decision, see Dennington v. Sec’y of Health &
Hum. Servs. (“Entitlement Decision”), No. 18-1303V, 2023 WL 2965239 (Fed. Cl. Apr. 17,
2023), detailed the facts, medical records, expert reports, and other evidence relevant to this case
comprehensively, and, as a result, the Court will only provide a summary of the relevant events
and evidence.
1. Previous GBS Diagnosis and Medical History
Prior to the vaccine at issue in this case, Petitioner had a medical history of abdominal
pain, allergic rhinitis, gastroesophageal reflux disease, asthma, obsessive-compulsive disorder,
anxiety, and irritable bowel syndrome. Id. at *1. On August 21, 2005, ten years prior to
receiving the vaccination at issue here, Petitioner visited South Hermann emergency room and
Texas Children’s Hospital (“TCH”) in Houston, Texas, complaining of bilateral facial paralysis,
weakness, ataxia, and unsteadiness/dizziness with lightheadedness. Id. As a result, Petitioner
was hospitalized. Id. While hospitalized, providers performed a head CT scan, lumbar puncture,
and an MRI of Petitioner’s spine, all of which came back normal, “with no evidence of
demyelination.” Id.
On August 24, 2005, Petitioner was diagnosed with GBS with bulbar involvement and
treated with intravenous immunoglobulin (“IVIG”).1 Id. at *2. The hospital then transferred her
from the intensive care unit to the progressive care unit, where she underwent occupational and
physical therapy. Id.; ECF No. 13-1 at 25. On August 26, 2005, Petitioner received a
rehabilitation evaluation at TCH. Entitlement Decision at *2. While the evaluation did not note
any cognitive impairment or gagging with oral intake, it did note that Petitioner had “impaired
oral motor function due to facial weakness” and “difficulty with some activities of daily living
(‘ADLs’) due to ataxia.” Id.; ECF No. 13-1 at 27. Petitioner continued rehabilitation, including
speech, physical, and occupational therapy three times per week. Entitlement Decision at *2;
ECF No. 13-1 at 27–28, 37. However, in her follow-up appointments at TCH, Petitioner
continued to complain of persistent fatigue and facial weakness, “although her overall motor
function had somewhat improved.” Entitlement Decision at *2. Petitioner continued her
rehabilitation therapy until she was discharged in April of 2006. Id.
1 IVIG is a blood product used to treat patients with antibody deficiencies, including neurological
disorders. See Jolles, Sewell & Misbah, Clinical Uses of Intravenous Immunoglobulin, NCBI (2005),
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1809480/ (last visited Aug. 8, 2023).
2

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Three and a half years later, on September 11, 2009, Petitioner underwent another
neurology consultation at the Houston Neurological Institute. Based on that consultation, Dr.
Kathleen Eberle, M.D. concurred that “Petitioner’s presentation was suggestive of the ‘Miller
Fisher variant of [GBS] and/or Bickerstaff’s brainstem encephalitis.’” Id. (quoting ECF No. 7-
10 at 1) (alterations in original). On January 7, 2010, Petitioner underwent an electromyogram
that showed “evidence of a ‘chronic sensorimotor neuropathy, predominantly demyelinating.’”
Id. (quoting ECF No. 7-10 at 5). Several days later, Dr. Eberle wrote a letter that stated that
Petitioner had been diagnosed with a variant of GBS in 2005, had “never achieved full
recovery,” had “some residual weakness and incoordination in the limbs,” tended “to fatigue
quickly,” and continued “to have weakness in the muscles of her face and . . . abnormal
movements/spasms in the face related to aberrant nerve regeneration.” Id.; ECF No. 17-1 at 1.
2. 2015 Vaccination and GBS Treatment
Six years later, on August 30, 2015, Petitioner, then 25 years old, went to the emergency
room at the Kingwood Medical Center (“Kingwood”) in Kingwood, Texas for a rash and abscess
after scraping her foot on an “old rusty pole.” Entitlement Decision at *3. Petitioner received a
Tdap vaccination. Id. Two days later, on September 1, 2015, Petitioner returned to Kingwood,
reporting numbness and tingling that was worse in her lower extremities. Id. She also
complained that her “foot just kinda fe[lt] asleep.” Id. However, a physical examination did not
show any abnormalities. Id. Petitioner’s mother insisted that Petitioner needed to see a
neurologist, and the two of them left Kingwood and went to TCH, where Petitioner complained
of numbness on the left side of her face, leg, and toes. Id. Petitioner also reported that she had
experienced a two-day fever, as well as nausea earlier that day. Id. Petitioner’s mother indicated
that Petitioner’s symptoms were similar to those she experienced ten years earlier at the onset of
her previous GBS episode in 2005. Id. When examined, Petitioner exhibited a normal
respiratory exam, presented no signs of headaches or neck rigidity, and showed “full bilateral
upper and lower extremity strength against resistance in all flexors and extensors . . . .” Id. She
did, however, exhibit “decreased sensation in her left upper and lower extremities and left face.”
Id.
Later that same day, Plaintiff was transferred and admitted to Houston Methodist
Hospital, where neurologist Robert Smith, M.D., evaluated Petitioner for possible GBS. Id.
Upon a motor examination, Petitioner presented full strength in the right upper and lower
extremities, but reduced strength in the left upper and lower extremities, as well as mild right
facial weakness. Id. “The differential diagnosis,” he stated, “included acute disseminated
encephalomyelitis and GBS, along with possible nonorganic cause of weakness.” Id. (internal
quotations and citations omitted). The next day, on September 2, 2015, Petitioner underwent
both a lumbar puncture and a brain MRI that produced normal results. Id. However, Petitioner
still showed evidence of decreased reflexes, and her electromyography/nerve connection studies
(“EMG/NCS”) test showed decreased F-waves. Id.
Petitioner’s neurological evaluation also noted that Petitioner “had 4+/5 strength in the
left upper and lower extremities with normal strength on the right and a decreased 1+/4 reflex at
the left knee, a normal 2+/4 reflex at the right knee, and absent reflexes at the ankles bilaterally.”
3

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Id. The evaluation further indicated that Petitioner “had mild objective weakness and subjective
numbness on the left side, and, because of her history of a previous episode of the Miller-Fisher
variant of GBS. . . [and] concern about a recurrence . . . [,] she was given five doses of IVIG.”
Id.
3. Treatment
Petitioner reported that her symptoms improved over the course of her IVIG treatment,
and she was discharged on September 6, 2015. Id. at *4. Her discharge note included a
“‘concern[] for a possible recurrence of GBS.’” Id. (quoting ECF No. 7-7 at 369–70). At a
follow-up appointment on October 13, 2015, Dr. Smith evaluated Petitioner for chronic
inflammatory demyelinating polyradiculoneuropathy (“CIDP”) and took note of her medical
history, including recurrent GBS versus CIDP, viral infections, flulike symptoms, diarrhea,
weakness, and Tdap vaccinations. Id. At this particular evaluation, Petitioner presented with
“nystagmus, abnormal facial expression and weakness, decreased hearing to finger rub,
decreased reflexes, and decreased sensation to light touch in all extremities.” Id. Dr. Smith
specifically noted that Petitioner experienced worsening CIDP, “slightly worsened proximal
weakness,” and suppressed reflexes in the upper extremities. Id. As a result, Dr. Smith
prescribed IVIG two days per month and suggested that Petitioner return to physical therapy. Id.
Over the next few weeks, Petitioner attended several physical therapy sessions at Kindred
Rehabilitation Hospital before she “discharged herself due to the long drive to therapy” on
November 17, 2015. Id. On December 10, 2015, Petitioner met with Dr. Smith for bilateral
hearing loss, CIPD, and mild memory loss. Id. She underwent IVIG treatment at the time and
reported that her limb endurance had improved, and her previous facial sensory dysesthesias had
resolved. Id. However, her posture and balance problems continued. Id. Dr. Smith suggested a
neuropsychology referral due to Petitioner’s baseline deficits from her “previous postvaccination
event . . . .” Id. Dr. Smith also discussed the following with Petitioner: vestibular rehabilitation,
when GBS is actually CIDP, when therapy for a chronic problem can help repair in a recurrent
but inactive process, and central nervous system involvement in a post-vaccination central and
peripheral nervous system injury. Id. Dr. Smith referred Petitioner to physical and occupational
therapy and ordered an EMG/NCS. Id.
Several months later, on March 16, 2016, Petitioner saw Dr. Smith for a follow-up
appointment regarding her recurrent GBS. Id. Petitioner was not receiving IVIG treatment at
the time and, while she was clinically stable, she was experiencing issues with limb posture and
endurance. Id. Petitioner also had “ongoing weakness in multiple muscles . . . in both the upper
and lower extremities.” Id. Dr. Smith diagnosed Petitioner with “GBS, bilateral hearing loss
(due to [the] initial episode of GBS), and mild memory disturbance from ‘post episode of post-
vaccination GBS+ . . . with balance and memory changes similar to those from [the] previous
episode 10 years earlier.’” Id. (quoting ECF No. 7-9 at 34). On April 6, 2016, Petitioner’s
repeat EMG/NCS “showed evidence of a ‘diffuse polyradiculopathy with previous denervation
and incomplete reinnervation.’” Id. at *5 (quoting ECF No. 28-1 at 7-9.).
In December 2016, “Petitioner’s most recent EMG ‘documented no new active lesions
(not ongoing CIDP), but still showed evidence of distal demyelination residual yet to recover
4

Case 1:18-vv-01303-ZNS Document 68 Filed 10/06/23 Page 5 of 16
from her most recent episode of weakness.’” Id. (quoting ECF No. 7-9 at 3, 17). In addition,
Petitioner was still experiencing continuing deficits in “fatigue, endurance, and focus, with
milder deficits in weakness and sensory function.” Id. At a follow-up visit on May 25, 2018,
Dr. Smith noted that, while Petitioner was slowly improving in strength and endurance, she still
experienced ongoing weakness of the extremities, decreased to absent reflexes, and weakness of
the facial muscles. Id. As a result, Dr. Smith’s diagnosis was once again GBS, “though
Petitioner ‘[i]nitially [had] some features suggestive of CIDP . . .’ with lower facial weakness
due to recurrent GBS, and bilateral hearing loss after her initial episode of GBS.” Id. (quoting
ECF No. 7-9 at 30). Petitioner’s last visit with Dr. Smith in the record was on March 13, 2019.
Id. (citing ECF No. 17-2 at 18).
B. Expert Reports
The Court will summarize the reports of the parties’ expert witnesses, which the Chief
Special Master’s decision recounted more comprehensively. See Entitlement Decision at *5–11.
1. Petitioner’s First Expert Report (Carlo Tornatore, M.D.)
Dr. Tornatore, a board-certified neurologist, a Professor and Chairman of the Department
of Neurology at Georgetown University Medical Center, and Chairman and Neurologist-in-Chief
of the Department of Neurology at Medstar Georgetown University Hospital in Washington,
D.C., completed two written reports for Petitioner supporting her assertion that the Tdap vaccine
can cause GBS and that it did so in this case. Id. at *5 (citing ECF Nos. 38-1 & 43-1). First,
“Dr. Tornatore opined that Petitioner has GBS, which he defined as an autoimmune
demyelinating neuropathy of the peripheral nervous system.” Id. at *6. Dr. Tornatore contended
that “foreign antigens (e.g., viral or bacterial infection or vaccination) result in activation of the
immune system—a normal mechanism to clear the offending antigen. . . . However, in rare
cases, the activation is misdirected, and both the humoral and cellular arms of the immune
system (the innate and adaptive responses, respectively) attack components of its own nervous
system.” Id. (citation omitted).
In regard to GBS specifically, Dr. Tornatore asserted that “the target of the immune
response is the myelin (and in some cases the axons) of the peripheral nervous system,” and
“[t]he resulting injury is manifested clinically by numbness and weakness of the extremities,
truncal muscles and muscles of the face and neck.” Id. Thus, according to Dr. Tornatore,
unilateral and bilateral facial weakness, like that experienced by Petitioner, is a common
symptom of GBS. Id. Based on Petitioner’s two episodes of GBS, her first beginning on August
21, 2005, and her second on September 1, 2015, Dr. Tornatore characterized Petitioner’s
diagnosis as “recurrent GBS.” Id. According to Dr. Tornatore, Petitioner’s symptoms and test
results after both episodes—including facial diplegia, motor weakness, early acute proximal
demyelination, normal cerebrospinal fluid protein levels, and nadir within four weeks of onset—
are consistent with early GBS. Id.
Next, Dr. Tornatore contended that the Tdap vaccine can theoretically cause GBS. Id.
He asserted that the pathogenesis of GBS “is affected by molecular mimicry post-exposure to
viral or bacterial antigens (which in turn resemble or mimic, host structures—meaning antibodies
5

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to the foreign antigens mistakenly attack the self).” Id. Dr. Tornatore cited several sources2 to
support his assertion that GBS can be associated with the Tdap vaccine and concluded “that the
Tdap vaccine more likely than not could result in autoimmune peripheral nerve demyelination
clinically presenting as GBS.” Id. Moreover, Dr. Tornatore indicated that Petitioner’s medical
history was consistent with his causation theory because other than the Tdap vaccine, Petitioner
had no other prior events that could have caused the GBS. Id. at *7. Dr. Tornatore also pointed
to the fact that, in Petitioner’s medical records, her most recent doctor, Dr. Smith, implied the
possibility of Tdap-induced GBS. Id.
In conclusion, Dr. Tornatore opined that the prompt timeframe for Petitioner’s
symptoms’ onset (within forty-eight hours of receiving the Tdap vaccination) was medically
acceptable. Id. This is because a quick response to a second antigenic challenge was reasonable
within a twenty-four hour period when a patient’s immune system was previously primed by an
earlier exposure to the Tdap vaccine, as Petitioner’s was here. Id. Dr. Tornatore cited several
pieces of literature to support his assertion, including literature discussing “the acceleration of
the immune response after previous exposure . . . .” Id. (citing Lawrence B. Schonberger et al.,
Guillain-Barré Syndrome Following Vaccination in the National Influenza Immunization
Program, United States, 1976–1977, 110 AM. J. EPIDEMIOLOGY 105, 120–22 (1979), filed as
ECF No. 47-4).
2. Respondent’s Expert Report (Timothy Vartanian, M.D., Ph.D.)
Dr. Vartanian, a board-certified neurologist, who is a professor at Weill Cornell Medical
College and an attending neurologist at New York Presbyterian Hospital, completed a written
report for Respondent supporting the contention that there was no causal relationship between
Petitioner’s Tdap vaccine and her GBS symptoms. Id. at *8. In his report, Dr. Vartanian first
acknowledged that Petitioner’s symptoms in 2005 (acellularity, elevated protein levels,
enhancement of the seventh and eighth nerve complex, and uncommon facial symptoms) were
consistent with GBS. Id. Dr. Vartanian also agreed that Petitioner’s 2015 episode showed
symptoms often associated with GBS. Id. However, Dr. Vartanian opined that further testing
and Petitioner’s medical record did not establish an evolution of symptoms that suggested new
autoimmune or inflammatory demyelination and, therefore, did not support the conclusion that
Petitioner experienced a recurrence of GBS in 2015. Id. Dr. Vartanian did not offer an
alternative diagnosis in his report. Id.
2 Dr. Tornatore cited the following in this report: Schonberger et al., supra, at 120–22. N.
Souayah et al., Guillain-Barre Syndrome After Vaccination in United States: A Report from the
CDC/FDA Vaccine Adverse Event Reporting System (1990–2005), 11 NEUROMUSCULAR DISEASE 1, 5
(2009), filed as Ex. 45 (ECF No. 47-7) (“[o]ur results suggest that vaccines other than influenza vaccine
can be associated with GBS.”). F. E. Shaw et al., Postmarketing Surveillance for Neurologic Adverse
Events Reported After Hepatitis B Vaccination, 127 AM. J. EPIDEMIOLOGY 337, 344–50 (1988), filed as
Ex. 44 (ECF No. 47-6); M. Khamaisi et al., Guillain-Barré Syndrome Following Hepatitis B Vaccination,
22 CLINICAL & EXPERIMENTAL RHEUMATOLOGY 767, 768–69 (2004), filed as Ex. 51 (ECF No. 57-2).
ECF No. 38-1 (“Tornatore First Report”) 22–24.
6

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Furthermore, Dr. Vartanian maintained that reliable medical literature3 did not support
Dr. Tornatore’s contention that the Tdap vaccine could cause an autoimmune process mediated
by molecular mimicry and lead to GBS. Id. at *9. Dr. Vartanian went on to opine that
Petitioner’s medical history was inconsistent with the explanation that the Tdap vaccine caused
her injury. Id. at *10. First, Dr. Vartanian noted that the cause of Petitioner’s 2005 bout of GBS
was incorrectly attributed to a Tdap vaccination that the record does not confirm as having
actually occurred, and the notes in Petitioner’s medical record also acknowledged the possibility
of multiple other antecedent infections that could have been the cause of Petitioner’s GBS. Id.;
see also ECF No. 41 (“Vartanian Report”) at 11. Second, with regard to Petitioner’s 2015 GBS
incident, Dr. Vartanian indicated that Petitioner once again showed symptoms of other
antecedent infections (an abscess on her foot from a nail, fever, and nausea) that could have been
the cause of her GBS, especially since, according to Dr. Vartanian, “antecedent gastrointestinal
or respiratory infections are by far most closely associated with GBS, whereas the Tdap vaccine
has only anecdotal associations.” Vartanian Report at 11; Entitlement Decision at *10. Finally,
Dr. Vartanian opined that Petitioner’s onset, one and a half days after her Tdap vaccination, was
not enough time for humoral or cellular immunity to cause an injury to the nervous system
because, while the memory cells can respond quickly when confronting the same previously-
encountered pathogen (or vaccine), in most cases, it still takes about four days for a memory
response to result in an effective immune reaction. Entitlement Decision at *10; Vartanian
Report at 16.
3. Petitioner’s Second Expert Report (Carlo Tornatore, M.D.)
Dr. Tornatore wrote a second report in response to Dr. Vartanian’s report. See ECF No.
43-1 (“Tornatore Second Report”); Entitlement Decision at *7. In that report, Dr. Tornatore
maintains that GBS was Petitioner’s proper diagnosis in 2015 because: (1) Petitioner’s
September 2, 2015, electromyography (“EMG”) results showed signs of an acute inflammatory
3 Dr. Vartanian cited the following in his report: W. Yih et al., An Assessment of the Safety of
Adolescent and Adult Tetanus–Diphtheria–Acellular Pertussis (Tdap) Vaccine, Using Active Surveillance
for Adverse Events in the Vaccine Safety Datalink, 27 VACCINE 4257, 4261 (2009), filed as Ex. A, Tab 18
(ECF No. 42-18) (“[w]e found no evidence of an association between Tdap and any of the five predefined
adverse events [including GBS] in a surveillance period that included 660,245 doses of Tdap over the
course of 145 weeks”); J. Nelson et al., Adapting Group Sequential Methods to Observational
Postlicensure Vaccine Safety Surveillance: Results of a Pentavalent Combination Dtap-IPV-Hib Vaccine
Safety Study, 177 AM. J. EPIDEMIOLOGY 131, 131 (2013), filed as Ex. A, Tab 13 (ECF No. 42-13) (“[n]o
increased risk was detected among 149,337 DTaP-IPV-Hib vaccinees versus historical comparators for
any outcome, including . . . Guillain-Barré syndrome . . . .”); J. Tuttle et al., The Risk of Guillain-Barre
Syndrome After Tetanus-Toxoid-Containing Vaccines in Adults And Children in The United States, 87
AM. J. PUB. HEALTH 2045, 2045–47 (1997), filed as Ex. D (ECF No. 58-1) (concluding that if an
association exists, it must be extremely rare and not of public health significance); M. Daley et al., Safety
of Diphtheria, Tetanus, Acellular Pertussis and Inactivated Poliovirus (Dtap–IPV) Vaccine, 32 VACCINE
3019, 3019 (2014), filed as Ex. A, Tab 6 (ECF No. 42-6) ([T]here was no evidence of increased risk for
any of the pre-specified adverse events monitored.”); R. Baxter et al., Lack of Association of Guillain-
Barre Syndrome with Vaccinations, 57 CLINICAL INFECTION DISEASES 197, 197 (2013), filed as Ex. A,
Tab 1 (ECF No. 42-1) (finding no evidence of an increased risk of GBS following vaccinations of any
kind). Vartanian Report at 14–16.
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process of the proximal nerve roots; (2) following her EMG report, Petitioner was immediately
treated with IVIG, the typical treatment for GBS; and (3) Petitioner’s follow-up EMG showed
signs of improvement, indicating the effectiveness of the immunotherapy treatment and the
monophasic course of her illness, thus indicating to Dr. Tornatore that Petitioner had GBS.
Tornatore Second Report at 27; Entitlement Decision at *7.
In response to Dr. Vartanian’s assertion regarding molecular mimicry, Dr. Tornatore
maintained that Dr. Vartanian did not dispute the scientific mechanisms of molecular mimicry in
his report. Entitlement Decision at *7. Dr. Tornatore went on to suggest that while Dr.
Vartanian contended there was a lack of epidemiologic data to support a causal relationship
between GBS and the Tdap vaccine, Dr. Tornatore opined that epidemiology cannot rule out rare
events such as vaccine injuries. Id. Finally, Dr. Tornatore also disagreed with Dr. Vartanian’s
opinion regarding Petitioner’s onset and argued that the immune response could possibly result
in a neurologic injury within 48 hours of vaccination because, immediately after exposure to a
foreign antigen, there is a measurable increase in the immune response, making Petitioner’s one-
and-a-half-day onset medically acceptable. Id. at *8.
C. Procedural History
On August 28, 2018, Petitioner filed a petition for compensation under the Vaccine Act,
alleging that she suffered a recurrent episode of GBS as a result of the Tdap vaccine she received
on August 30, 2015. ECF No. 1. Expert reports were filed through January 2022. Entitlement
Decision at *10. On January 11, 2022, the Chief Special Master issued an Order determining
that the claim could be decided by a ruling on the record. Id. Petitioner filed her motion and
accompanying exhibits in support of a ruling on the record on April 22, 2022. ECF No. 46.
Respondent filed a response on July 7, 2022, ECF No. 53, and Petitioner filed a reply on August
1, 2022, ECF No. 55. The Chief Special Master issued a ruling on the record denying
entitlement on March 23, 2023, determining that “Petitioner ha[d] not preponderantly established
that the Tdap vaccine [s]he received could cause GBS, or that it did so to her in a medically-
acceptable timeframe.” Entitlement Decision at *1. Petitioner timely filed a motion for review
on April 24, 2023, setting forth the following objections:
1. The [Chief] Special Master improperly elevated Petitioner’s burden of proof under
Althen prong one by requiring direct medical proof of the mechanism of injury and by
overlooking evidence of petitioner’s pre-existing aberrant immune system.
2. The Chief Special Master’s analysis of Althen prongs two and three were similarly
infected by the Chief Special Master’s imposition of a heightened standard regarding
the evidence he would accept for Petitioner to prove that she actually received a Tdap
vaccine prior to the onset of her GBS in 2005.
ECF No. 61. Respondent filed a response on May 24, 2023, ECF No. 64, and the Court held oral
argument on July 27, 2023.
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DISCUSSION
A. Standard of Review
Under the Vaccine Act, this Court has jurisdiction to review the entitlement decisions of
special masters. See 42 U.S.C. § 300aa–12(e)(1). In reviewing a special master’s decision, the
Court may:
(A) uphold the findings of fact and conclusions of law of the special master and
sustain the special master’s decision,
(B) set aside any findings of fact or conclusion of law of the special master found
to be arbitrary, capricious, an abuse of discretion, or otherwise not in accordance
with law and issue its own findings of fact and conclusions of law, or
(C) remand the petition to the special master for further action in accordance with
the court’s direction.
42 U.S.C. § 300aa–12(e)(2). In other words, “[u]nder the Vaccine Act, the Court of Federal
Claims reviews [a special master’s] decision to determine if it is ‘arbitrary, capricious, an abuse
of discretion, or otherwise not in accordance with the law.’” Markovich v. Sec’y of Health &
Hum. Servs., 477 F.3d 1353, 1355–56 (Fed. Cir. 2007), cert. denied, 552 U.S. 816 (2007) (citing
42 U.S.C. § 300aa–12(e)(2)(B)).
With regard to factual determinations, the Court does not “reweigh the factual evidence,
assess whether the special master correctly evaluated the evidence, or examine the probative
value of the evidence or the credibility of the witnesses—these are all matters within the purview
of the fact finder.” Porter v. Sec’y of Health & Hum. Servs., 663 F.3d 1242, 1249 (Fed. Cir.
2011). If the “special master’s factual findings are ‘based on evidence in the record that [is] not
wholly implausible, the Court cannot find that a special master was arbitrary and capricious.’”
Id. (quoting Lampe v. Sec’y of Health & Hum. Servs., 219 F.3d 1357, 1363 (Fed. Cir. 2000)). In
other words, “[i]f the special master has considered the relevant evidence of record, drawn
plausible inferences and articulated a rational basis for the decision, reversible error will be
extremely difficult to demonstrate.” Hines on Behalf of Sevier v. Sec’y of Dep’t of Health &
Hum. Servs., 940 F.2d 1518, 1528 (Fed. Cir. 1991); see also Hodges v. Sec’y of Health & Hum.
Servs., 9 F.3d 958, 961 (Fed Cir. 1993) (“[O]n review, the Court of Federal Claims is not to
second guess [a s]pecial [m]aster[’]s fact-intensive conclusions; the standard of review is
uniquely deferential for what is essentially a judicial process.”); Munn v. Sec’y of Health & Hum.
Servs., 970 F.2d 863, 870 (Fed. Cir. 1992) (arbitrary and capricious standard applied to “both
fact-findings and fact-based conclusions . . . is a standard well understood to be the most
deferential possible”). In short, the Court affords a special master a great deal of deference with
regard to factual conclusions and how the evidence is weighed, and, as a result, a petitioner faces
a heavy burden to overturn a special master’s factual and evidentiary determinations.
As it relates to questions of law, under the “not in accordance with law” standard, the
Court may review de novo a special master’s decision with regard to statutory or other purely
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legal issues. H.L. v. Sec’y of Health & Hum. Servs., 129 Fed. Cl. 165, 169 (2016); accord Hines,
940 F.2d at 1527 (“The ‘not in accordance with the law’ aspect of the standard of review is . . .
involved [in cases in which there is a] dispute over statutory construction or other legal issues.”).
Finally, the Court may review a special master’s discretionary rulings for “abuse of discretion.”
Munn, 970 F.2d at 870 n.10.4
B. Petitioner’s Legal Standard Under the Vaccine Act
Under the Vaccine Act, a petitioner may seek compensation for two different types of
vaccine injuries. First, a petitioner is entitled to compensation “when an injury or condition
listed in the Vaccine Injury Table . . . begins to manifest itself within the time specified in the
Table for the vaccine in question.” Hines, 940 F.2d at 1524 (citing 42 U.S.C. §§ 300aa–
11(c)(1)(C)(i), 300aa–14(a)). In these so-called “table injury cases,” causation is presumed. Id.
Second, “for injuries not listed in the Table, or which do not occur within the time period
stipulated in the Table, the Vaccine Act authorizes recovery only if the petitioner proves actual
causation.” Id. at 1524–25 (citing 42 U.S.C. § 300aa–11(c)(1)(C)(ii)). A petitioner bears the
burden of establishing actual causation in a non-table case by a preponderance of the evidence.
Broekelschen v. Sec’y of Health & Hum. Servs., 618 F.3d 1339, 1345 (Fed. Cir. 2010). If a
petitioner satisfies his or her burden, then the burden shifts to the Secretary to prove “[by] a
preponderance of the evidence that [the petitioner’s injury] is due to factors unrelated to the
administration of the vaccine described in the petition.” See 42 U.S.C. § 300aa–13(a)(1)(B);
accord Walther v. Sec’y of Health & Hum. Servs., 485 F.3d 1146, 1150 (Fed. Cir. 2007). Indeed,
if a petitioner makes out a prima facie case, he or she “bears no burden to rule out possible
alternative causes.” de Bazan v. Sec’y of Health & Hum. Servs., 539 F.3d 1347, 1352 (Fed. Cir.
2008) (citing Walther, 485 F.3d at 1149–50).
Here, Petitioner’s asserted injury—GBS allegedly caused by the Tdap vaccine—is a
“non-table” injury. Entitlement Decision at *11; 42 C.F.R. § 300.3(a). To prove actual
causation by a preponderance of the evidence in a non-table case, a petitioner must demonstrate
the following:
(1) a medical theory causally connecting the vaccination and the injury; (2) a logical
sequence of cause and effect showing that the vaccination was the reason for the
injury; and (3) a showing of a proximate temporal relationship between vaccination
and injury.
4 “An abuse of discretion may be found when (1) the court’s decision is clearly unreasonable,
arbitrary, or fanciful; (2) the decision is based on an erroneous conclusion of the law; (3) the court’s
findings are clearly erroneous; or (4) the record contains no evidence upon which the court rationally
could have based its decision.” Simmons v. Sec’y of Health & Hum. Servs., 875 F.3d 632, 635 (Fed. Cir.
2017) (citing Hendler v. United States, 952 F.2d 1364, 1380 (Fed. Cir. 1991)). However, the abuse of
discretion is not frequently applied in vaccine appeals. See Munn, 970 F.2d at 870 n.10 (abuse of
discretion standard “will rarely come into play except where the special master excludes evidence”);
Caves v. Sec’y of Health & Hum. Servs., 100 Fed. Cl. 119, 131 (2011) (abuse of discretion is “applicable
when the special master excludes evidence or otherwise limits the record upon which he relies”). Here,
the Chief Special Master did not exclude evidence or limit the record in any way; therefore, the abuse of
discretion standard is not applicable.
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Althen v. Sec’y of Health & Hum. Servs., 418 F.3d 1274, 1278 (Fed Cir. 2005).
To meet prong one, “a petitioner must provide a reputable medical or scientific
explanation that pertains specifically to the petitioner’s case, although the explanation need only
be ‘legally probable, not medically or scientifically certain.’” Broekelschen, 618 F.3d at 1345
(quoting Knudsen v. Sec’y of Health & Hum. Servs., 35 F.3d 543, 548–49 (Fed. Cir. 1994)). A
petitioner need not establish a plausible medical theory with conclusive evidence. See Solak v.
Sec’y of Health & Hum. Servs., No. 14–869 V, 2020 WL 9173158, at *19 (Fed. Cl. Spec. Mstr.
Feb. 19, 2020) (“A petitioner may satisfy the first Althen prong without resort to medical
literature, epidemiological studies, demonstrations of a specific mechanism, or a generally
accepted medical theory.”). Nonetheless, a theory “that lacks any empirical support will have
limited persuasive force.” Caves v. Sec’y of Dep’t of Health & Hum. Servs., 100 Fed. Cl. 119,
134 (2011), aff’d sub nom. Caves v. Sec’y of Health & Hum. Servs., 463 F. App’x 932 (Fed. Cir.
2012).
To satisfy prong two, a petitioner “must show that the vaccine was the ‘but for’ cause of
the harm,” Pafford v. Sec’y of Health & Hum. Servs., 451 F.3d 1352, 1356 (Fed. Cir. 2006),
often by using facts and medical opinions derived from the petitioner’s medical records, Althen,
418 F.3d at 1278. However, while medical records and statements of treating physicians should
be evaluated and weighed carefully, they are not binding on a special master or this Court. See
42 U.S.C. § 300aa–13(b)(1)(B) (“Any such diagnosis, conclusion, judgment, test result, report,
or summary shall not be binding on the special master or court.”); Snyder v. Sec’y of Health &
Hum. Servs., 88 Fed. Cl. 706, 746 n.67 (2009) (“[T]here is nothing . . . that mandates that the
testimony of a treating physician is sacrosanct—that it must be accepted in its entirety and
cannot be rebutted.”).
The third Althen prong requires a petitioner to prove a “medically-acceptable temporal
relationship between the vaccination and the onset of the alleged injury.” 418 F.3d at 1281.
Specifically, a petitioner needs to submit “proof that the onset of symptoms occurred within a
timeframe which, given the medical understanding of the disorder’s etiology, it is medically
acceptable to infer causation.” de Bazan, 539 F.3d at 1352. The third prong closely links with
the first prong because the acceptable timeframe must coincide with a petitioner’s theory of how
a particular vaccine can cause the injury. Id. In reality, the third Althen prong can be broken
down into two steps: (1) “establish the timeframe for which it is medically acceptable to infer
causation, that is, the timeframe in which symptoms would be expected to arise if the [disorder]
was caused by the vaccination”; and (2) “show that the onset of the [disorder] occurred during
this causation period.” Shapiro v. Sec’y of Health & Hum. Servs., 101 Fed. Cl. 532, 542 (2011).
C. Althen Prong One As Applied to Petitioner’s Claim
As stated above, the Chief Special Master determined that Petitioner failed to meet the
required burden of proof for all three Althen prongs. Accordingly, in order to successfully
challenge the Chief Special Master’s determination, Petitioner must demonstrate that the Chief
Special Master’s decision was arbitrary, capricious, or otherwise not in accordance with law with
regard to all three prongs of the Althen test. See 42 U.S.C. § 300aa–12(e)(2)(B). Because the
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Court determines that Petitioner fails to demonstrate that the Chief Special Master’s
determination with regard to Althen prong one was in error, the Court must deny her motion for
review.5
Under Althen prong one, Petitioner must provide a “medical theory causally connecting
the vaccination [Tdap] and the injury [GBS].” 418 F.3d at 1278. Such a theory must be “legally
probable, not medically or scientifically certain.” Knudsen, 35 F.3d at 549. Petitioner need not
resort to medical literature, epidemiological studies, demonstration of a specific mechanism, or a
generally accepted medical theory. Andreu ex rel. Andreu v. Sec’y of Health & Hum. Servs., 569
F.3d 1367, 1378–79 (Fed. Cir. 2009) (citing Capizzano v. Sec’y of Health & Hum. Servs., 440
F.3d 1317, 1325–26 (Fed. Cir. 2006)). However, “[a] petitioner must provide a ‘reputable
medical or scientific explanation’ for [his or her] theory [, and thus] [w]hile it does not require
medical or scientific certainty, it must still be ‘sound and reliable.’” Boatmon v. Sec’y of Health
& Hum. Servs., 941 F.3d 1351 (Fed. Cir. 2019) (quoting Moberly ex rel. Moberly v. Sec’y of
Health & Hum. Servs., 592 F.3d 1315, 1322 (Fed. Cir. 2010) and Knudsen, 35 F.3d at 548–49).
Here, Petitioner attempts to satisfy Althen’s first prong with the medical theory that the
Tdap vaccine could cause GBS via molecular mimicry, a concept that is well-established in
immunology. See Pierson v. Sec’y of Health & Hum. Servs., No. 17–1136 V, 2022 WL 322836,
at *23 (Fed. Cl. Spec. Mstr. Jan. 19, 2022) (“Molecular mimicry is a well-established theory in
the Vaccine Program and has been persuasively linked to several autoimmune conditions.”)
(collecting cases). Despite the fact that molecular mimicry itself is a well-established concept,
the Chief Special Master found that Petitioner failed to establish “that the Tdap vaccine could
cause GBS with sufficient reliable scientific or medical evidence.” Entitlement Decision at *19.
According to the Chief Special Master, “more must be done to preponderantly establish
causation than simply rais[ing] the flag of molecular mimicry as a generally-reliable concept.”
Id. “Instead, claimants and their experts must provide sufficient connective evidence to allow a
conclusion that it is more likely than not the specific vaccine in question that could cause the
relevant injury.” Id. (internal quotations omitted).
In her motion for review, Petitioner argues that the Chief Special Master “improperly
elevated petitioner’s burden of proof under Althen prong one” by requiring “direct proof of
molecular mimicry as the mechanism” of injury. ECF No. 62 at 7, 12. She posits that the Chief
Special Master did so by failing to adequately address (1) the Schonberger article cited by
Petitioner’s expert, Dr. Tornatore, that discusses an association between GBS and the swine flu
and tetanus vaccines, and (2) the cases in which other special masters have found that the Tdap
vaccine can cause GBS. See id. at 11–12. Petitioner further argues that the Chief Special Master
did not address Petitioner’s recurrence of GBS and, in doing so, “entirely failed to ask the right
question.” Id. at 13–14. This, according to Petitioner, heightened her burden of proof for Althen
prong one. Moreover, Petitioner asserts that the cases and medical literature cited by both the
Chief Special Master and Respondent’s expert, Dr. Vartanian, “which did not observe an
association between the Tdap vaccine and injury,” did not discuss “individuals who suffered
multiple episodes of GBS,” like Petitioner, and thus were given more weight than they deserved.
See id. at 13–15. Accordingly, Petitioner asserts that the “[Chief Special Master’s] approach
5 Given this finding regarding prong one, the Court need not address Plaintiff’s arguments
regarding prongs two and three of the Althen test.
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[was] contrary to Program precedent from the Federal Circuit and the underlying purpose of the
Vaccine Act.” Id. at 12.
Although Petitioner raises several issues with the Chief Special Master’s determination
regarding Althen prong one, the Court need not address much of Petitioner’s argument as the
Court must concur with the Chief Special Master that Petitioner simply failed to show the
necessary causal relationship between the Tdap vaccine and GBS. While Petitioner and Dr.
Tornatore put forth the well-established medical theory of molecular mimicry as the mechanism
through which the Tdap vaccine could cause GBS, nowhere in Dr. Tornatore’s expert reports,
nor in Petitioner’s briefs, do they specifically tie the Tdap vaccine to GBS through molecular
mimicry.
For example, Dr. Tornatore explains that during the process of molecular mimicry, if a
viral or bacterial antigen in a vaccine shares homology with host antigens, the vaccine’s immune
response will be “directed at both the injected antigens and host antigens,” resulting in
autoimmunity. Tornatore First Report at 23. Dr. Tornatore goes on to suggest the possibility
that “the pathogenesis of GBS is due to molecular mimicry post-exposure to viral or bacterial
antigens.” Id. at 22. However, Dr. Tornatore never actually explains how molecular mimicry
might occur from the Tdap vaccine specifically, nor does he elaborate on how molecular
mimicry could cause the specific autoimmune system reaction that could cause GBS. To quote
the Chief Special Master, Dr. Tornatore
did not attempt to establish the kind of homology between vaccine antigens and self
structures in the nerves that is a common starting point for molecular mimicry when
offered as a mechanistic explanation. He also pointed to no specific antibody
created in response to the Tdap vaccine that might cross-react against nerve myelin
in the manner GBS is believed to progress.
Entitlement Decision at *19. Instead, Dr. Tornatore’s expert opinion deals in generalities and
uses the well-established concept of molecular mimicry to offer a generally accepted, but
unspecified, theory that a vaccine can result in molecular mimicry, which can then cause an
autoimmune reaction resulting in injury. In fact, because Dr. Tornatore does not offer any
specific explanation as to the distinct connection between Tdap, molecular mimicry, and GBS,
one could take Dr. Tornatore’s causation theory and substitute any table vaccine (e.g., the
measles vaccine) and any autoimmune disorder (e.g., autoimmune encephalitis) and Dr.
Tornatore’s expert report’s discussion of molecular mimicry would require absolutely no
changes. That is how general his molecular mimicry theory is—it does not matter which vaccine
and which autoimmune disorder are plugged in. But Althen prong one requires more.
There is nothing in Dr. Tornatore’s report that explains or even alludes to what antigens
or structures in the Tdap vaccine could share homology with possible host antigens and how
these antigens could react in the manner GBS is believed to progress. Additionally, the GBS
literature that Dr. Tornatore cites to in support of his causation theory speaks only to a causal
relationship between GBS and the tetanus and swine flu vaccines. See Tornatore First Report at
22–24. The literature upon which he relies make no mention of any causal connection between
GBS and the Tdap vaccine. See id. Dr. Vartanian, on the other hand, cited literature that
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specifically found no evidence of an association between the Tdap vaccine and GBS.6 Vartanian
Report at 14–16. Finally, and unfortunately for Petitioner, she offers no other evidence—outside
of Dr. Tornatore’s report—to support her Althen prong one argument that the Tdap vaccine could
cause GBS via molecular mimicry.
As a result, the Court must uphold the Chief Special Master’s determination that
Petitioner did not meet her burden under the first Althen prong. Although Petitioner argues that
the Chief Special Master “increase[d] the burden placed on [P]etitioner[] in offering a scientific
theory linking vaccine to injury” and “improperly required petitioner to prove the specific
biologic mechanism as to how Tdap vaccine generally can cause GBS,” ECF No. 62 at 9, 14,
neither the Chief Special Master, nor the Court, is asking Petitioner to prove anything. Rather,
Petitioner (and Petitioner’s expert) simply failed to explain how the specific vaccine at issue
(Tdap) could possibly cause the experienced autoimmunity (GBS). Neither Dr. Tornatore, nor
Petitioner, answered the question that must be addressed to satisfy the first Althen prong: what
reputable medical theory causally connects the received vaccination (Tdap) and the experienced
injury (GBS)? Instead, they simply offered the reliable and generally-accepted medical theory of
molecular mimicry but never explained how that theory could form a causal connection
specifically between the Tdap vaccine and GBS. And while Petitioner need not identify or prove
that the Tdap vaccine actually caused GBS via molecular mimicry, Knudsen, 35 F.3d at 549,
simply citing “molecular mimicry” as the causation theory does not meet the Althen prong one
burden without additional evidence that offers some actual connection between molecular
mimicry, Tdap, and GBS. See, e.g., McKown v. Sec’y of Health & Hum. Servs., No. 15-1451 V,
2019 WL 4072113, at *50 (Fed. Cl. Spec. Mstr. July 15, 2019) (citing Devonshire v. Sec’y of the
Dep’t of Health & Hum. Servs., No. 99-031 V, 2006 WL 2970418, at *15 (Fed. Cl. Spec. Mstr.
Sept. 28, 2006), aff’d sub nom. Devonshire v. Sec’y of Dep’t of Health & Hum. Servs., 76 Fed.
Cl. 452 (2007)).
In addition, Petitioner also argues that the Chief Special Master heightened the Althen
prong one standard by failing to address the fact that Petitioner suffered a recurrence of GBS,
which, Petitioner asserts, “formed the entire basis of Dr. Tornatore’s two expert reports.” ECF
No. 62 at 14. Petitioner goes on to make a “challenge-rechallenge” argument, i.e., the idea that
she was exposed to the Tdap vaccine, reacted in a certain way, was given the same vaccine
again, and reacted to it in a similar way as before. See id. at 14–15; Nussman v. Sec’y of Health
& Hum. Servs., No. 99–500–V, 2008 WL 449656, at *9 (Fed. Cl. Spec. Mstr. Jan. 31, 2008),
aff’d, 83 Fed. Cl. 111 (2008). Petitioner’s argument fails for two reasons. First, Petitioner
discusses this argument in relation to Althen prong one, but challenge-rechallenge arguments
relate to the second Althen prong. Nussman, 2008 WL 449656, at *12 n.6 (“The challenge-
rechallenge model is not a medical theory. The challenge-rechallenge paradigm is a method,
based in logic, that can assist in proving that a vaccine caused an injury. As such, challenge-
rechallenge is discussed in the second prong of Althen. The underlying logic can be used in a
6 Petitioner argues that the Chief Special Master incorrectly rejected Dr. Tornatore’s theory “in
favor of Dr. Vartanian’s citation to several pieces of medical literature ‘which did not observe an
association between the Tdap vaccine and injury.’” ECF No. 62 at 13 (citing Entitlement Decision at
*19). The Court need not address this so-called battle of the experts argument because, as mentioned
above, Petitioner’s expert never actually addresses the real question contemplated by Althen prong one:
how could the Tdap vaccine itself cause GBS specifically via molecular mimicry?
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variety of disciplines, not just medicine.”). Thus, it is irrelevant whether the Chief Special
Master correctly addressed Petitioner’s recurrent GBS in his discussion of the first Althen prong.
Second, as discussed above, even if a challenge-rechallenge argument was relevant to an Althen
prong one analysis, Petitioner still fails to establish how recurrent GBS could possibly be
causally connected to the Tdap vaccine via molecular mimicry or any other reputable medical
theory.
Finally, Petitioner addresses, and the Chief Special Master concedes, the fact that other
special masters have found that the Tdap vaccine can cause GBS. See, e.g., Mohamad v. Sec’y of
Health & Hum. Servs., No. 16–1075 V, 2022 WL 711604, at *18 (Fed. Cl. Spec. Mstr. Jan. 27,
2022); see also Swaiss v. Sec’y of Health & Hum. Servs., No. 15–286 V, 2019 WL 6520791, at
*23–27 (Fed. Cl. Spec. Mstr. Nov. 4, 2019); Harris v. Sec’y of Health & Hum. Servs., No. 18–
944 V, slip op. (Fed. Cl. Spec. Mstr. Feb. 21, 2023). However, as both Respondent and the Chief
Special Master point out, there are also cases in which special masters have found that petitioners
have failed to show reliable scientific evidence of an association between the Tdap vaccine and
GBS. See, e.g., Tompkins v. Sec’y of Health & Hum. Servs., No. 10–261 V, 2013 WL 3498652
(Fed. Cl. Spec. Mstr. June 21, 2013), mot. for review den’d, 117 Fed. Cl. 713 (2014); Isaac v.
Sec’y of Health & Hum. Servs., No. 08–601 V, 2012 WL 3609993 (Fed. Cl. Spec. Mstr. July 30,
2012), mot. for review den’d, 108 Fed. Cl. 743 (2013), aff’d, 540 F. App’x 999 (Fed. Cir. 2013).
These sets of cases differ from one another in several critical ways.
First, in Mohamad, the petitioner won on Althen prong one because respondent had
publicly accepted the proposition that a DTap vaccine can cause GBS. See generally Mohamad,
2022 WL 711604, at *9–18. Second, in Swaiss, the special master acknowledged “that there
[were] not significant verified case reports, population studies, and animal experiments
supporting an association between Tdap vaccine and the most common GBS variants . . . .”
2019 WL 6520791, at *27. However, he found that the petitioner still met Althen prong one
because the “case involve[d] a GBS variant involving selective damage of the small fibers” that
are difficult to obtain objective evidence of and are thus “likely to be overlooked,” resulting in
limited case reports on the matter. Id. Therefore, the special master found that “[p]etitioner
should not be faulted for the lack of published literature on point with his case.” Id. Finally, in
Harris, Petitioner’s Althen prong one argument relied on other reputable medical theories other
than molecular mimicry alone. See generally No. 18–944 V, slip op.
In contrast, but similar to the case at hand, the special master in Isaac, another case in
which Dr. Tornatore served as an expert, found that the petitioner did not provide a causal
connection between the Tdap vaccine and GBS because while “Dr. Tornatore explained how
molecular mimicry might cause GBS” and “described the process of molecular mimicry . . . he
did not link tetanus or Td vaccination to GBS by the process of molecular mimicry.” See 2012
WL 3609993, at *21. The same thing occurred here: Dr. Tornatore suggested that molecular
mimicry could cause GBS, he explained generally how molecular mimicry occurs, but he failed
to identify how the Tdap vaccine itself could result in molecular mimicry in a way that could
then go on to cause GBS specifically. As a result, the Court finds that, no matter what standard
the Chief Special Master applied in his Althen prong one analysis, he was correct to the extent
that Petitioner failed to provide an adequate medical theory casually connecting Petitioner’s
injury to the vaccine she received.
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CONCLUSION
For the foregoing reasons, the Court finds that Petitioner has failed to establish that the
Chief Special Master’s Entitlement Decision with regard to Althen prong one was arbitrary,
capricious, or otherwise not in accordance with law. Accordingly, Petitioners’ Motion for
Review is DENIED, and the decision of the Chief Special Master is SUSTAINED. The Clerk
of the Court shall enter judgment accordingly.
IT IS SO ORDERED.
s/ Zachary N. Somers
ZACHARY N. SOMERS
Judge
16