Rachel McCulloch v. HHS - HPV, autoimmune limbic encephalitis, intractable epilepsy, and subsequent developmental delays (2015)

On May 11, 2009, Rachel McCulloch filed a petition on behalf of her daughter, A.M., alleging that a Human Papillomavirus (HPV) vaccine, specifically Gardasil, administered on August 16, 2007, caused A.M. to develop autoimmune limbic encephalitis (ALE), intractable epilepsy, and subsequent developmental delays. The petition was amended on December 7, 2009, to further detail these allegations.

The respondent, the Secretary of Health and Human Services, countered that the evidence was insufficient to establish causation and suggested an alternative diagnosis of Febrile Infection-Related Epilepsy Syndrome (FIRES). Special Master Thomas L.

Gowen issued a Ruling on Entitlement on May 22, 2015, finding that A.M. suffered from ALE and that the HPV vaccine was the cause-in-fact of her injuries. A stipulated damages award was entered on November 28, 2016.

A.M., born October 8, 1994, received her second dose of the Gardasil vaccine on August 16, 2007, at age twelve. Approximately five weeks later, on September 22, 2007, she developed a fever and sore throat, and on September 26, a strep culture was positive.

The following day, September 27, 2007, she experienced her first tonic-clonic seizure and was hospitalized. Extensive diagnostic workups at Miami Children's Hospital ruled out known viral, bacterial, fungal, genetic, metabolic, toxic, nutritional, congenital, and paraneoplastic causes.

A.M. was placed in a medically induced coma on October 3, 2007, and discharged on January 2, 2008, without significant recovery. She received her third HPV dose on February 21, 2008, which was immediately followed by a fever and another seizure.

Her condition persisted despite multiple antiseizure medications, leading to a mesial temporal lobectomy in December 2008, during which the surgeon noted scarring in the hippocampus. By 2013, A.M. had profound cognitive impairment and intractable epilepsy.

Petitioner's theory of causation, supported by experts Dr. Lawrence Steinman and Dr.

Svetlana Blitshteyn, posited that the second Gardasil dose triggered an autoimmune limbic encephalitis through molecular mimicry. They argued that sequence homologies between HPV types 16 and 18 (components of Gardasil) and aquaporin-4 (AQP-4) water channels in the brain could lead to immune-mediated damage, disrupting osmotic homeostasis and causing neuronal hyperexcitability and seizures.

Respondent's expert, Dr. Arun Venkatesan, proposed a diagnosis of FIRES and challenged the ALE diagnosis and the molecular mimicry mechanism, arguing the homology evidence was insufficient and A.M.'s presentation lacked classic ALE features.

Special Master Gowen rejected the FIRES diagnosis, finding that ALE was supported by the medical literature, particularly in pediatric cases where seizures can dominate the clinical picture. He found the Althen prongs satisfied: (1) Dr.

Steinman's evidence of amino acid homology between Gardasil components and AQP-4, coupled with literature linking AQP-4 dysfunction to seizures, was persuasive; (2) the seizure activity was localized to the limbic area, alternative causes were excluded, and A.M.'s prior autoimmune disorder (idiopathic thrombocytopenic purpura) suggested susceptibility; and (3) this prong was stipulated. The damages were stipulated, resulting in a total award of $1,428,188.00 in a lump sum, which included $1,055,056.01 for lost earnings, $250,000.00 for pain and suffering, and $123,131.99 for Year One life care expenses.

Additionally, $41,216.61 was awarded for past unreimbursable expenses, and $58,535.37 to satisfy a Florida Medicaid lien. The award also included a life-contingent annuity for future life care expenses.

Later proceedings addressed the award of attorneys' fees and costs, including the costs associated with maintaining A.M.'s guardianship, which were affirmed by Judge Charles F. Lettow.