Following a Hantavirus outbreak aboard a cruise ship that departed Argentina in April 2026, false claims spread on social media alleging that Pfizer's COVID-19 vaccine caused the disease. Experts including virologists and infectious disease specialists have confirmed that COVID-19 vaccines do not contain live viruses and cannot transmit Hantavirus. The outbreak, which affected a cruise ship with suspected links to Honduras, resulted in at least 3 deaths and 7 confirmed cases; the WHO has stated the outbreak poses no pandemic risk, as Hantavirus is naturally transmitted from infected rodents and remains rare.