S.L. v. HHS - Influenza, autoimmune encephalitis/status epilepticus and death (2025)

On December 21, 2020, Ye Xia, on behalf of her minor child S.L., filed a petition seeking compensation under the National Vaccine Injury Compensation Program. Petitioner alleged that an influenza vaccine administered to S.L. on February 1, 2020, caused her to develop autoimmune encephalitis, ultimately leading to her death.

S.L., who was eleven years old at the time of vaccination, had no prior medical history. She presented with flu-like symptoms and a fever on February 1, 2020, and received the flu vaccine during that visit.

Three days later, her condition worsened, and she was taken to the emergency room exhibiting seizure-like activity, a high fever, and an altered mental state. Extensive testing and treatment followed, with physicians considering various diagnoses including sepsis, meningitis, encephalitis, and autoimmune conditions.

Despite numerous treatments, S.L. experienced refractory status epilepticus and was eventually transitioned to comfort care, passing away on May 4, 2020. The death certificate listed "Super Refractory Status Epilepticus, suspected autoimmune encephalitis" as the cause of death.

Petitioner's expert, Dr. AHM Mahbubul Huq, opined that the flu vaccine, in combination with a possible viral infection, triggered S.L.'s condition through inflammation and immune response, potentially via molecular mimicry.

Respondent's experts, Dr. Michael Sweeney and Dr.

Hayley Gans, argued that S.L.'s condition was most likely caused by an adenovirus infection, which triggered an inflammatory response leading to Febrile Infection-Related Epilepsy Syndrome (FIRES), and that the flu vaccine was unlikely to be a significant factor. The court found that while FIRES was the most reasonable clinical description, it did not rule out an autoimmune or vaccine-associated pathogenesis.

The court ultimately found entitlement, concluding that the flu vaccine, in the context of S.L.'s existing febrile illness, likely played a substantial role in her disease process, meeting the preponderance of the evidence standard. A damages award of $500,000.00 for pain and suffering ($250,000.00) and the death benefit ($250,000.00), plus $4,530.37 for past medical expenses, was granted.

The decision was issued by Chief Special Master Brian H. Corcoran.