A hantavirus outbreak on a cruise ship kills 3 people and infects 11 more, triggering a 42-day quarantine in Nebraska. New York Times health reporter Apoorva Mandavilli explains how the virus spreads, why public health officials downplayed transmission risks, and what the CDC's slow response reveals about pandemic preparedness. The Andes virus, a type of hantavirus found in Argentine rodents, spreads human-to-human with an estimated reproduction rate of 2.1, lower than COVID-19 but carries a 30% fatality rate compared to COVID's lower rate.