Health experts and fact-checkers are debunking viral claims that hantavirus is a side effect of COVID-19 vaccines or caused by tourism in Argentina [1, 2, 3].
This surge of misinformation arrives as a localized hantavirus outbreak occurs in South America, providing a catalyst for anti-vaccine narratives to regain traction online. The spread of these theories threatens public health by eroding trust in medical science and distracting from the actual causes of the virus.
Social-media users on TikTok, Facebook, and X have shared claims that Pfizer's COVID-19 vaccine causes hantavirus [1, 2]. These posts have garnered over 10,000 shares [3]. However, the Snopes fact-check team said Pfizer has never reported hantavirus as a side effect of its COVID-19 vaccine, and there is no scientific evidence linking the two [1].
Separate narratives have targeted Ushuaia, Argentina, where 12 confirmed hantavirus cases have been reported since March 2026 [2]. Some online posts suggest that tourists visiting the region brought the virus to the area [3]. A tourism board spokesperson said the recent cases in Ushuaia are linked to increased contact with infected rodents, not to tourists visiting the region [2].
These claims are often packaged under a "Plandemic Covid 2.0" narrative, which suggests the virus is part of a manufactured pandemic [3]. France 24 fact-checkers said there is no credible data supporting this narrative [3].
The misinformation campaign has targeted audiences in the U.S., the UK, and Argentina [1, 2]. Experts said the strategy relies on reviving discredited narratives from previous years to fuel political polarization and anti-vaccine sentiment [3].
“Pfizer has never reported hantavirus as a side-effect of its COVID-19 vaccine”
The resurgence of these theories demonstrates how localized health events can be weaponized by misinformation networks to undermine vaccine confidence. By linking a rodent-borne zoonotic virus to pharmaceutical products, promoters of these theories attempt to create a false pattern of vaccine harm, which can lead to decreased immunization rates and increased public panic during actual outbreaks.
