K.A. v. HHS - Tdap, Guillain-Barré syndrome (2022)

K.A., a 51-year-old medical researcher, received a Tdap vaccine on August 12, 2013. He subsequently developed symptoms consistent with Guillain-Barré syndrome (GBS), with onset reported around August 29, 2013, approximately 18 days after vaccination.

K.A. filed a petition alleging the Tdap vaccine caused his GBS, an off-Table injury. The case involved extensive expert testimony from both sides, with petitioner's expert, Dr.

Lawrence Steinman, proposing two causation theories: first, that the alum adjuvant in the Tdap vaccine could cause GBS, and second, that molecular mimicry between vaccine components and nerve structures could trigger GBS. Respondent's expert, Dr.

Kathleen Collins, argued that K.A.'s symptoms were more likely caused by an intercurrent upper respiratory infection (URI) or influenza-like illness (ILI) that he experienced prior to the onset of GBS. The Chief Special Master denied entitlement, finding that K.A. failed to establish by a preponderance of the evidence that the Tdap vaccine caused his GBS under either of the proposed theories.

The decision noted that the medical records strongly supported the conclusion that an intercurrent URI was the more likely cause of K.A.'s GBS, and that the expert testimony did not sufficiently establish a causal link between the vaccine and the injury. K.A. appealed this decision, arguing that his requests for an infectious disease expert were improperly denied and that the Chief Special Master misconstrued the law regarding causation.

The reviewing court affirmed the Chief Special Master's decision, finding no abuse of discretion in denying additional experts or a hearing, and agreeing that the evidence did not preponderantly support a vaccine-related injury. The case was ultimately denied.