Nicholas Gillon v. HHS - Tdap, Guillain-Barré syndrome (GBS) (2026)
Case summary [AI summaries can sometimes make mistakes]
On January 15, 2021, Nicholas Gillon filed a petition alleging that a tetanus-diphtheria-acellular pertussis (Tdap) vaccination administered on June 5, 2019 caused Guillain-Barre syndrome and associated sensory deficits. He was 43 years old at vaccination.
About sixteen days later, Mr. Gillon began experiencing numbness and weakness that progressed into areflexia, decreased sensation, and diffuse weakness.
His diagnostic workup included MRI and lumbar puncture, which were not conclusive for GBS but did not rule it out. His treating neurologist, Dr.
David W. Schmidt, diagnosed GBS and treated him with IVIG.
Mr. Gillon improved significantly but reported residual symptoms beyond six months.
Petitioner's neurology expert, Dr. David M.
Simpson, proposed molecular mimicry as the mechanism linking Tdap vaccine to GBS. Respondent's expert, Dr.
Brian C. Callaghan, argued that an antecedent gastrointestinal illness was a more likely trigger.
After reconsidering respondent's objections, the Special Master found that Mr. Gillon satisfied all three Althen prongs: a reliable molecular-mimicry theory, a logical sequence of cause and effect in his medical course, and a medically acceptable onset interval of about sixteen days.
Entitlement was granted on February 20, 2026, with damages still pending.
Theory of causation
Adult petitioner, age 43; Tdap vaccine June 5, 2019; GBS with sensory deficits beginning about 16 days later. ENTITLEMENT GRANTED, damages pending. Theory: molecular mimicry. Petitioner expert Dr. David M. Simpson; respondent expert Dr. Brian C. Callaghan argued antecedent GI illness. Treating neurologist Dr. David W. Schmidt diagnosed GBS and gave IVIG. All Althen prongs satisfied. Petition filed January 15, 2021; entitlement February 20, 2026.
Source PDFs
USCOURTS-cofc-1_21-vv-00752