2 verifications about Hantavirus Pulmonary Syndrome Hantavirus Pulmonary Syndrome ×
“As of May 7, 2026, the case-fatality rate of Hantavirus Pulmonary Syndrome in the United States is about 35%.”
The best U.S. evidence places HPS case-fatality in the mid-to-high 30s, so “about 35%” is broadly accurate. A 1993–2024 summary reports 34.9%, while CDC public-facing materials often round higher, to roughly 38–40%. The claim is reasonable as an approximation, but it understates the higher figure often used by CDC.
“Pfizer Inc. listed hantavirus pulmonary syndrome as a potential adverse event of special interest (AESI) or possible side effect in its COVID-19 vaccine safety monitoring documents for the BNT162b2 (Comirnaty) vaccine.”
Pfizer’s safety-monitoring materials did include hantavirus pulmonary syndrome on an AESI-style surveillance list for BNT162b2. That supports the claim’s core factual point. But this does not show Pfizer identified it as a confirmed or likely side effect, and official labeling and regulator product information do not list it as an established adverse reaction.