Hantavirus cruise ship outbreak revives COVID-era conspiracy theories

A hantavirus outbreak on a Dutch cruise ship has reignited a wave of COVID-19-era conspiracy theories across social media — including false claims of forced vaccines, depopulation plots and election manipulation — as misinformation researchers warn the false narratives that emerged during the pandemic never fully disappeared.

The episode illustrates how public health emergencies can become fertile ground for entrenched disinformation campaigns — a pattern that puts communities at risk when viral conspiracy theories erode trust in legitimate health guidance, researchers say.

A passenger on the Dutch-flagged MV Hondius contracted hantavirus before boarding in Argentina and subsequently spread the infection to others aboard the vessel, according to AFP. The World Health Organization said the risk to the general public from the ship's passengers remains minimal.

Within days of the outbreak becoming public, social media posts began circulating language borrowed from the 2020 "Plandemic" pseudo-documentary, with users falsely alleging the virus is a bioweapon or a side effect of COVID-19 vaccines. Conspiracy theories also claimed the outbreak was engineered to justify mail-in ballots ahead of the November 2026 U.S. elections, The Korea Times reported.

InfoWars founder Alex Jones amplified the claims on social media. "LOCKDOWN ALERT: Globalists Launch Covid 2.0 As Hantavirus Spreads Worldwide. Just Like A Light Switch," Jones said on X, according to The Korea Times.

Researchers said the speed of the false narratives' revival was itself a warning sign. "The almost-immediate resurrection of Covid-19 era conspiracy theories is a reminder that misinformation doesn't simply disappear once the crisis that yielded them is over," said Yotam Ophir, head of the University at Buffalo's Media Effects, Misinformation and Extremism lab.

Despite a surge of posts promoting ivermectin as a cure, clinical evidence does not support the claim. "There is extreme misinformation about ivermectin. Outside of laboratory tests, ivermectin has not proven effective in treating infections," said John Lednicky, a virologist at the University of Florida College of Public Health and Health Professions, according to AFP. There are no approved vaccines or known cures for hantavirus, which is typically transmitted from infected rodents and can cause respiratory, cardiac and hemorrhagic symptoms.

Anti-establishment political figures and medical voices — including former U.S. Rep. Marjorie Taylor Greene and Texas otolaryngologist Mary Talley Bowden — were among those promoting unproven alternatives, The Korea Times reported.

Misinformation researchers note that conspiracy theories blaming elites for manufactured disease outbreaks have centuries-old roots, and that since the COVID-19 pandemic, anti-vaccine sentiment has become deeply entangled with political identity — making such theories harder to dislodge with each successive health emergency.