Marissa Sheppard v. HHS - Influenza, mixed connective tissue disease and polymyositis (2025)

Marissa Sheppard filed a petition alleging that her influenza vaccination on September 19, 2017, caused her to develop arthralgia, fatigue, and muscle weakness, diagnosed as mixed connective tissue disease (MCTD) and polymyositis. The case proceeded as an off-Table claim, meaning Ms.

Sheppard had to prove causation-in-fact. She presented medical records and expert opinions, including from her treating rheumatologist, Dr.

Jagindra Mangru, who supported her MCTD diagnosis. Her expert, Dr.

Marc Serota, proposed a theory of causation based on molecular mimicry and autoimmune syndrome induced by adjuvants (ASIA), suggesting the flu vaccine could trigger autoimmune responses. Respondent, the Secretary of Health and Human Services, contested the diagnosis and causation.

The respondent's experts, Dr. Chester Oddis and Dr.

Emanual Maverakis, questioned the MCTD diagnosis, citing inconsistent laboratory results and the absence of key clinical features. They also criticized Dr.

Serota's causation theory, arguing it was not sound or reliable, lacked specific links to MCTD, and that the ASIA hypothesis had been rejected in prior cases. The Special Master found that Ms.

Sheppard failed to establish a sound and reliable theory of causation under the first prong of the Althen test, noting that prior cases have not successfully linked flu vaccines to connective tissue disorders like MCTD. Furthermore, the Special Master found that Ms.

Sheppard did not prove a logical sequence of cause and effect under the second prong, as her treating physician did not opine on vaccine causation, and the temporal relationship alone was insufficient. Consequently, the petition was dismissed for failure to meet the burden of proof.