Michael Pavan v. HHS - Varicella, Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) (2020)
Case summary [AI summaries can sometimes make mistakes]
On January 24, 2014, Michael Pavan, as next friend of J.P., a minor, filed a petition alleging that J.P. suffered a significant aggravation of his pre-existing Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) as a result of receiving the varicella vaccination on January 28, 2011. Petitioner argued that the varicella vaccine triggered an immune response, specifically an anti-idiotype response that mimicked molecular structures on the myelin-associated glycoprotein (MAG), leading to damage and exacerbation of J.P.'s CIDP.
Petitioner's experts, Drs. Margulies and Axelrod, supported this theory, emphasizing the temporal proximity between the vaccination and the worsening of J.P.'s symptoms.
Respondent's experts, Drs. Bingham and MacGinnitie, contested this, arguing that CIDP, particularly in children, is primarily T-cell mediated and that anti-idiotype antibodies are generally protective, not pathogenic, in autoimmune diseases.
They also questioned the temporal association, suggesting that a T-cell mediated response would be more rapid. The court reviewed J.P.'s medical history, noting pre-existing conditions such as high bilirubin, GERD, anemia, and vitamin D deficiency.
Symptoms of fatigue were noted in the months leading up to the vaccination. Following the vaccination, J.P. experienced increased fatigue, withdrawal from activities, emotional changes, and physical issues including limb failure, grip issues, fine motor issues, and a left eye droop.
These symptoms led to a diagnosis of CIDP confirmed by EMG/nerve conduction studies in June 2011. J.P. subsequently received IVIG treatments and other therapies.
The Special Master considered the six-part test for off-Table significant aggravations established in Loving. The Special Master found that the petitioner failed to establish a reliable medical theory connecting the varicella vaccine to the aggravation of CIDP, noting that the literature presented suggested anti-idiotypes tend to suppress immune responses rather than cause damage, and that pediatric CIDP is primarily T-cell mediated.
Furthermore, the Special Master found that while there was a temporal association (approximately 21 days between vaccination and symptom worsening), it was not sufficient to establish causation, especially given the lack of a persuasive medical theory and the evidence suggesting J.P.'s symptoms began prior to the vaccination and followed a relapsing-remitting course consistent with the disease's natural progression. Ultimately, the Special Master concluded that the evidence was insufficient to demonstrate a causal role for the varicella vaccination in exacerbating J.P.'s CIDP, and therefore, the petition was denied and dismissed.
Petitioner was represented by Scott W. Rooney, and respondent was represented by Kyle E.
Pozza. Special Master Thomas L.
Gowen issued the decision.
Theory of causation
Petitioner alleged that the varicella vaccination administered on January 28, 2011, caused a significant aggravation of J.P.'s pre-existing Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). Petitioner's experts, Drs. Margulies and Axelrod, proposed a theory involving an immune response to the varicella vaccine, specifically an anti-idiotype response. They posited that glycoprotein B in the varicella vaccine is structurally similar to myelin-associated glycoprotein (MAG), a component of the peripheral nerve myelin. This molecular mimicry, they argued, could lead to an anti-idiotype antibody response that binds to MAG, causing damage to the myelin sheath and exacerbating CIDP. Dr. Axelrod suggested this mechanism could involve both B-cells and T-cells, and that the immune system's response, including the anti-idiotype network, could persist even after the vaccine is cleared, leading to ongoing damage. Petitioner's experts emphasized the temporal proximity between the vaccination and the worsening of J.P.'s symptoms, noting onset of significant fatigue and neurological changes approximately 21 days post-vaccination. Respondent's experts, Drs. Bingham and MacGinnitie, countered that CIDP, particularly in children, is primarily a T-cell mediated autoimmune disease, not an antibody-mediated one. They argued that anti-idiotype antibodies are generally considered protective or regulatory, downregulating immune responses rather than causing damage. They also contended that the proposed mechanism did not align with the known pathophysiology of pediatric CIDP and that the temporal association was insufficient to establish causation, especially given evidence that J.P.'s symptoms predated the vaccination and followed a natural course of the disease. The Special Master found that the petitioner failed to establish a reliable medical theory under Loving prong four (Althen prong one), as the literature suggested anti-idiotypes are protective and the proposed mechanism did not adequately explain how it would cause T-cells to attack myelin. The Special Master also found that the petitioner failed to establish a logical sequence of cause and effect (Loving prong five/Althen prong two) and an acceptable temporal association (Loving prong six/Althen prong three), noting that J.P.'s symptoms appeared to have an earlier onset and a relapsing-remitting course consistent with the natural progression of CIDP, and that the temporal link was not sufficient without a persuasive medical theory. The petition was denied. Attorneys for petitioner were Scott W. Rooney, and for respondent was Kyle E. Pozza. Special Master Thomas L. Gowen issued the decision on August 28, 2020.
Source PDFs
USCOURTS-cofc-1_14-vv-00060