Background
Sherrill Cote received hepatitis B and influenza vaccines on May 10, 2016, and developed joint pain and swelling shortly afterward. She was later diagnosed with severe new-onset rheumatoid arthritis. Her medical records also documented a more-than-20-year smoking history and symptoms of an upper respiratory infection near the time her joint symptoms began. None of her treating physicians attributed her rheumatoid arthritis to either vaccination.
Cote sought compensation under the National Childhood Vaccine Injury Act for an off-table injury. Her experts proposed several mechanisms by which the vaccines might cause rheumatoid arthritis, including molecular mimicry, but neither expert relied on or discussed a challenge-rechallenge theory, and Cote experienced no rechallenge event. The special master found her experts and supporting literature unpersuasive and concluded that she had not proved either that the vaccines can cause rheumatoid arthritis or that they caused her condition. Cote moved for review in the Court of Federal Claims.
The Court’s Holding
The court denied Cote’s motion for review and affirmed the special master’s decision. Applying the highly deferential arbitrary-and-capricious standard to the special master’s factual findings, the court held that the special master reasonably evaluated the competing experts and medical literature and rationally concluded that Cote failed to establish a reliable medical theory under the first prong of the Althen causation test. The special master did not require scientific certainty or proof of a specific biological mechanism; he found that Cote’s experts had not adequately supported their proposed theories.
The court also upheld the finding that Cote failed to establish the logical sequence of cause and effect required by Althen’s second prong. The special master permissibly considered Cote’s smoking history, respiratory infection, and the absence of treating-physician support when deciding whether she had made a prima facie causation showing. That analysis did not improperly shift the burden to Cote to eliminate alternative causes or accept a statutory “factor unrelated” defense, because the burden never shifted to the government after Cote failed to establish her prima facie case.
Key Takeaways
- An off-table Vaccine Act claimant must prove by a preponderance of the evidence both a reliable medical theory showing that the vaccine can cause the injury and a logical causal sequence showing that it did so in the claimant’s case.
- Capizzano did not establish that the hepatitis B vaccine causes rheumatoid arthritis, and its record differed materially because multiple treating physicians there attributed the condition to vaccination.
- A special master may consider documented alternative risk factors when assessing the petitioner’s prima facie case without requiring the petitioner to disprove every other possible cause.
Why It Matters
The decision illustrates the substantial deference given to special masters’ evaluation of expert credibility and scientific evidence in Vaccine Act cases. A reviewing court will not reweigh competing evidence when the special master considered the record, drew plausible inferences, and explained the decision rationally.
The opinion also clarifies the distinction between considering other possible causes during the petitioner’s threshold causation showing and applying the government’s affirmative “factor unrelated” defense after a prima facie case has been established. The opinion was filed under seal on August 6, 2026, and publicly reissued without redactions on August 24, 2026.