Heather Thomas v. HHS - Influenza, Lambert-Eaton myasthenic syndrome (2023)

Heather Thomas, a 43-year-old woman, received an influenza vaccine on September 26, 2017. Thirteen days later, she began experiencing progressive leg weakness and unexplained bruising, which worsened over the following days.

She was initially diagnosed with Guillain-Barre syndrome (GBS) or myasthenia gravis and treated with IVIG. Further evaluation led to a diagnosis of acute motor axonal neuropathy (AMAN), and eventually, in January 2019, Lambert-Eaton myasthenic syndrome (LEMS) at the Mayo Clinic.

Ms. Thomas alleged that the influenza vaccine caused her LEMS.

She initially pursued a claim for GBS, which is on the Vaccine Injury Table, but later amended her petition to focus on LEMS, an off-Table condition. To support her claim, Ms.

Thomas presented expert testimony from Dr. Andrew Pachner, who theorized that the flu vaccine triggered dormant memory B cells specific for voltage-gated calcium channels (VGCCs) to produce antibodies attacking the neuromuscular junction, causing LEMS.

The respondent, the Secretary of Health and Human Services, presented expert testimony from Dr. Neil Romberg, who challenged Dr.

Pachner's theory. The court found that Ms.

Thomas failed to establish a persuasive medical theory connecting the flu vaccine to her LEMS, specifically criticizing the evidence supporting her defective B-cell signaling theory and a late-emerging bystander activation theory. While the court found that the timing of her LEMS onset was within an acceptable window after vaccination (Althen prong 3), it concluded she failed to prove causation-in-fact (Althen prong 2) due to a lack of persuasive evidence.

A treating physician's statement calling the vaccine association a "reasonable hypothesis" was deemed insufficient. Ultimately, the court denied Ms.

Thomas's claim, finding she did not meet her burden of proof for entitlement to compensation.