Portia Exum v. HHS - Tdap, autoimmune hepatitis (2025)

Portia Exum, a 30-year-old adult, received Tdap and MMR vaccines on August 20, 2018. She later developed autoimmune hepatitis (AIH), alleging the vaccines caused her condition.

Her symptoms, including fatigue and nausea, began approximately two months after vaccination, with elevated liver enzymes detected on October 26, 2018. She received treatment for AIH, which included medication and monitoring.

Petitioner presented expert testimony from Dr. Robert Gish, who theorized that the vaccines could have caused AIH through molecular mimicry and other immune activation mechanisms, citing various case reports.

Respondent presented expert testimony from Dr. Jeffrey Crippin and Dr.

Andrew MacGinnitie, who argued that the vaccines were not the cause of her AIH, pointing to other potential factors such as her travel history, anti-malarial medication, prior Epstein-Barr virus infection, and the idiopathic nature of AIH. The Chief Special Master initially denied her claim, finding she failed to establish causation.

This decision was reviewed by the Court of Federal Claims, which remanded the case for further explanation. On remand, the Chief Special Master again denied the claim, concluding that Petitioner failed to establish that the vaccines could cause AIH (Althen prong one) and that the evidence did not demonstrate the vaccines actually caused her AIH (Althen prong two), citing the lack of contemporaneous evidence of a vaccine reaction, the presence of confounding factors, and the persuasive testimony of Respondent's experts.

The Court of Federal Claims affirmed the denial, finding the Chief Special Master's reasoning to be well-supported and not arbitrary or capricious. Therefore, Portia Exum was not entitled to compensation.