Conspiracy theorists, wellness influencers, and grifters have already started promoting wild claims about the hantavirus outbreak that began aboard the MV Hondius, a cruise ship on the Atlantic.

Some conspiracy theorists compared the outbreak to the Covid-19 pandemic, claiming it was another effort to control the global population, while others pushed a false narrative that the Covid-19 vaccine caused hantavirus. Many others promoted ivermectin as a treatment, using the incident as a way to sell emergency medical kits featuring the antiparasitic drug typically used as a horse dewormer.

In more recent days, many of these same people spreading conspiracy theories have promoted the baseless and antisemitic claims that the entire incident is a false flag orchestrated by Israel.

Conspiracy theories flooding social media in response to breaking news are nothing new, but what is notable about those being pushed around the hantavirus outbreak is just how closely they echo the conspiracy theories promoted during the Covid-19 pandemic.

“One of the most striking shifts since the Covid pandemic is how rapidly misinformation narratives now organize themselves around emerging outbreaks,” Katrine Wallace, an epidemiologist at University of Illinois Chicago School of Public Health, tells WIRED.

“Within hours of the first hantavirus headlines, social media accounts were already promoting ivermectin, attributing the outbreak to Covid vaccines, and warning about a hantavirus vaccine that does not exist. The claims themselves were often contradictory, but that contradiction no longer appears to limit their spread.”

Once the hantavirus outbreak started making headlines around the world, conspiracy theorists and grifters jumped into action, spreading dangerously ill-informed claims and, of course, trying to sell people ivermectin.

“Ivermectin should work against it,” Mary Talley Bowden wrote on X. Bowden, a doctor, is a prominent promoter of medical misinformation who has promoted ivermectin as a treatment for Covid-19 and prescribed ivermectin to a Covid-19 patient. Hours after her first post on Hantavirus went viral, she followed up to say that she is selling ivermectin to Texans. Bowden did not respond to a request for comment.

Her post, which has been viewed 4 million times, was shared by former Congresswoman Marjorie Taylor Greene, who added that vitamin D and zinc would help fight the infection. Greene even claimed that not getting the Covid-19 vaccine had somehow allowed her to “develop natural immunity” against hantavirus.

Greene separately claimed, without evidence, that the pharmaceutical company Moderna had purposely manipulated the virus in order to allow them to cash in by developing a hantavirus vaccine. Greene did not respond to a request for comment.

Other prolific health disinformation promoters boosted the ivermectin claims, including Simone Gold, the founder of Covid denial group America's Frontline Doctors, and Peter McCullough, a disinformation peddler who promoted the “sudden death” conspiracy theory about the Covid-19 vaccine, which falsely claimed that those who received the shot were at risk of dropping dead without any warning.

McCullough is also the chief scientific officer for The Wellness Company, which has been described as “Goop for the GOP.” The company has used the hantavirus outbreak to promote a $325 “Contagion Emergency Kit” which includes both ivermectin and hydroxychloroquine.

All the false claims and posts about ivermectin gained enough traction online that the World Health Organization responded to say that there is no research to suggest ivermectin is an effective treatment for hantavirus.

Conspiracy theorists have, meanwhile, been pushing the baseless idea that a side effect of Covid vaccines includes a hantavirus infection.

“List of Pfizer Covid jab side effects includes Hantavirus pulmonary infection!” Andrew Bridgen, a former UK lawmaker who boosted Covid-19 conspiracy theories, wrote on Facebook in a post that included a screenshot of submissions Pfizer filed to the FDA in 2021 to get a biological license for its vaccine.

A Pfizer spokesperson confirmed to Reuters that the reference seen in the screenshot does not confirm that the vaccine causes hantavirus, but is simply a list of notable infections experienced by those trialling the vaccine in December 2020.

“This was entirely predictable and gives the lie to the grift,” Neil Stone, an infectious disease doctor who debunks disinformation online, tells WIRED. “There is no science behind it, they just shift any Covid-related conspiracy to any other disease.”

Many wellness influencers who downplayed the Covid-19 pandemic have also claimed the hantavirus is part of a grand scheme to control the population. As evidence, many people pointed to a 2022 post on X from an anonymous account that simply reads: “2023: Corona ended. 2026: Hantavirus.”

In recent days, the new conspiracy theory that falsely claims the hantavirus outbreak is a false flag attack perpetrated by Israel has exploded on X, where it’s become a trending topic.

The baseless conspiracy theory has also spread on other social media platforms including Instagram, Facebook, and TikTok, where many of the posts have been viewed hundreds of thousands of times. The theory is based solely on the claim that in Hebrew, the word “hanta” means “scam.” This doesn’t appear to actually be the case.

Social media platforms being used to amplify disinformation from unreliable sources in breaking news situations is not new; the problem is that more and more Americans get their health news from social media. Findings from a study by the Pew Research Center published this week from 2025 show that around half of Americans under 50 get their health and wellness information from podcasts and influencers.

“What concerns me is that this increasingly functions less like isolated viral misinformation and more like a standing information ecosystem that can rapidly attach itself to any new health event,” says Wallace. “In an environment where so many Americans get their health information from influencers and podcasts, repeated exposure to these narratives can shape how audiences interpret outbreaks before evidence-based public health communication has fully reached them.”