De Bazan v. Secy of HHS
In De Bazan v. Secy of HHS, 539 F.3d 1347 (Fed. Cir. 2008), petitioner alleged her acute disseminated encephalomyelitis (ADEM) occurred eleven hours after her tetanus vaccination. Id. at 1349-50.
ADEM is an autoimmune disorder affecting the central nervous system. Id. at 1350, n.1. Petitioner became a quadriplegic. Id. at 1350.
The testimony of respondents expert at the hearing concerned the brevity of the eleven-hour onset interval. The special master held that petitioners onset was too soon to be appropriate for vaccine causation.
However, a judge on the Court of Federal Claims reversed the special masters dismissal, concluding that petitioner had established a prima facie case. The Federal Circuit reversed, finding no error in the special masters conclusion that an eleven-hour onset was too soon to connote causation.
The Federal Circuit stated that a petitioner must provide preponderant proof that the onset of symptoms occurred within a timeframe for which, given the medical understanding of the disorders etiology, it is medically acceptable to infer causation-in-fact. Id. at 1352.
Since eleven hours was not sufficient time to produce molecules responsible for myelin destruction, the onset interval in De Bazan was inappropriate for causation. Id. at 1353, 1354.