Gary Davison v. HHS - Pneumococcal, Guillain-Barre syndrome (GBS), depression, and death by suicide (2025)

On September 12, 2019, Ronald Davison, as Executor of the Estate of Gary Davison, filed a petition alleging that Gary Davison suffered Guillain-Barré Syndrome (GBS) caused by a Prevnar 13 (pneumococcal) vaccine received on August 10, 2017. The petition also alleged that Gary Davison suffered depression leading to suicide as a consequence of his GBS.

Gary Davison was 71 years old at the time of vaccination and had a history of cerebral vascular accidents. Approximately ten days after vaccination, he developed symptoms consistent with GBS, including progressive weakness, numbness, and tingling in his extremities, along with leg pain and difficulty breathing.

His GBS diagnosis was confirmed by elevated protein in his cerebrospinal fluid and findings on an EMG/NCS study. During his hospitalization, he was intubated due to respiratory difficulty and expressed a desire to die, leading to a diagnosis of situational depression, though a full psychiatric evaluation was limited by his condition.

He was treated with IVIG and eventually extubated. After regaining decision-making capacity, he continued to report feeling down, and was treated with paroxetine.

He was discharged to rehabilitation and later home, but his condition worsened. He was hospitalized again briefly in December 2017.

His brother noted that upon returning home, Gary Davison became very depressed due to his weakness and perceived lack of recovery. He committed suicide on December 29, 2017.

Petitioner's expert, Nizar Souayah, M.D., opined that the Prevnar 13 vaccine caused the decedent's GBS through molecular mimicry and that the GBS was a substantial contributing factor and but-for cause of his depression and subsequent suicide, citing increased risks of depression and suicide in GBS patients. Petitioner's other expert, Lawrence Steinman, M.D., also proposed a molecular mimicry theory involving phosphoglycerol molecules in the vaccine cross-reacting with myelin tissue.

Respondent's experts, Peter Donofrio, M.D., and Harry Schroeder, Jr., M.D., Ph.D., disagreed that the pneumococcal vaccine is associated with GBS, suggesting the decedent's GBS occurred by chance. Respondent's expert Yang Zhang, Ph.D., also critiqued Dr.

Steinman's molecular mimicry theory. In a ruling on entitlement dated August 19, 2025, Special Master Daniel T.

Horner found that the petitioner had met the burden of proof under the Althen test, concluding that the Prevnar 13 vaccine caused Gary Davison's GBS and that his GBS was a substantial contributing factor and but-for cause of his death by suicide. On December 2, 2025, Special Master Horner issued a decision awarding compensation.

The parties stipulated to a total award of $500,000.00, consisting of $250,000.00 for past pain and suffering and $250,000.00 for the statutory benefit for a vaccine-related death. The award was to be paid as a lump sum via ACH deposit to petitioner's counsel's IOLTA account.