Background
Brenda Baughman received Tdap and Prevnar 13 vaccines on May 10, 2016. Over the following weeks and months, she experienced pain, numbness, and tingling, and testing led to a diagnosis of axonal sensory and mixed axonal and demyelinating motor polyneuropathy. She sought compensation under the National Childhood Vaccine Injury Compensation Program, alleging that the Tdap vaccine caused her condition.
Because her claimed injury was not listed on the Vaccine Injury Table, Baughman had to prove actual causation under the three-part Althen test. A special master denied compensation after finding that she had not shown by a preponderance of the evidence that Tdap can cause autoimmune axonal polyneuropathy or that her own condition was autoimmune. Baughman moved for review, arguing that the special master imposed an excessively demanding legal standard and irrationally weighed the expert opinions, medical literature, case reports, and treating physician’s assessment.
The Court’s Holding
The Court of Federal Claims denied Baughman’s motion for review and sustained the special master’s decision. It held that the special master applied the correct standard under Althen’s first prong. Although a petitioner need not prove a precise biological mechanism, Baughman relied on molecular mimicry as her proposed mechanism, so the special master properly evaluated whether that theory was sound and reliable for the particular combination of the Tdap vaccine and axonal polyneuropathy.
The court also upheld the special master’s weighing of the evidence as rational and supported by the record. Baughman’s expert identified neither a relevant homology nor a vaccine component that would cross-react within the body, and the literature concerning Guillain-Barré syndrome, influenza vaccines, and other neuropathies did not establish that Tdap can cause Baughman’s condition. The case reports largely showed temporal associations, and the treating physician’s assessment depended on a suspected vasculitis and rash that were not established by a preponderance of the evidence. Because failure to prove general causation under Althen’s first prong was dispositive, the court did not reach the dispute over the second prong.
Key Takeaways
- An Off-Table Vaccine Act claimant must prove by a preponderance of the evidence that the vaccine can cause the type of injury alleged.
- A claimant need not establish a precise biological mechanism, but a proposed molecular-mimicry theory must be supported reliably as applied to the vaccine and injury at issue.
- Temporal proximity, case reports suggesting an association, and evidence concerning different vaccines or neurological conditions did not establish general causation here.
Why It Matters
The decision illustrates the distinction between showing that molecular mimicry is a generally accepted concept and showing that it reliably explains a particular vaccine-injury pairing. Evidence supporting causation for another vaccine or a different neurological disorder may carry limited weight when the claimant cannot connect it to the specific condition alleged.
It also underscores the highly deferential review given to a special master’s factual findings and expert-credibility determinations. When the special master considers the relevant evidence, draws plausible inferences, and explains a rational basis for the result, disagreement over the evidence’s weight generally will not justify reversal.