AFP —Posts on social media claim recent monkeypox outbreaks are the result of a “side effect” of Pfizer’s Covid-19 vaccine. This is false; health experts say monkeypox cannot be contracted via Covid-19 vaccination, and Pfizer told AFP the virus is not a side effect of the shot.

“The Root Of Monkeypox? Internal Pfizer Document Reveals Vaccines Trigger ‘Autoimmune Skin Blistering,'” says the headline of a May 31, 2022 article from a blog called Down the Chupacabra Hole.

The text of the article goes on to say autoimmune diseases “are exponentially rising” and that “a rare skin malady dubbed ‘monkeypox’ is being diagnosed in highly vaccinated regions.”

Down the Chupacabra Hole says on its website that it explores “the nature of reality, conspiracies, ufology, cryptids & paranormal phenomena.” The blog has previously amplified conspiracy with stories about “lizard people.”

“Thoughts shared in these articles reflect the author’s opinion. Do not take these statements as medical advice,” the blog says in a disclaimer.

Multiple posts on social media have shared similar claims about the Pfizer vaccine. A May 26 Facebook post says monkeypox “is simply a well documented side effect (as admitted by Pfizer) to the mRNA vaccines.”

The posts are part of a pattern of online misinformation shared as monkeypox cases rise outside the West and Central African nations where it is endemic. On June 8, the World Health Organization (WHO) warned that more than 1,000 cases of monkeypox had been confirmed in non-endemic countries.

The notion that Pfizer’s Covid-19 vaccine is responsible for those cases is incorrect. Health experts told AFP monkeypox cannot be contracted via vaccination.

Monkeypox not a vaccine side effect

Keanna Ghazvini, senior associate of global media relations at Pfizer, told AFP that, while the pharmaceutical company “cannot verify the accuracy of claims and documents circulating on social media,” monkeypox “is not one of the listed known side effects of Pfizer’s Covid-19 vaccine.”

The company’s Covid-19 vaccine “does not contain any live virus and is completely synthetic. Furthermore, it does not shed any virus transmitting from human to human,” she said. “With monkeypox, human-to-human transmission occurs through close contact with infectious material from skin lesions of an infected person, through respiratory droplets in prolonged face-to-face contact, and through fomites.”

Paulo Verardi, an associate professor of virology and vaccinology at the University of Connecticut who does consulting work for Pfizer, said claims that monkeypox is a side effect of the Covid-19 vaccine are “completely untrue.”

Kari Debbink, a virologist and associate scientist at the Johns Hopkins Bloomberg School of Public Health, agreed, saying “you cannot contract monkeypox from the Covid-19 vaccine.

“None of the Covid-19 vaccines have any part of the monkeypox virus in them,” she said.

To support the claims in its article, Down the Chupacabra Hole cites reports in the Vaccine Adverse Event Reporting System (VAERS), a database run by the US Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) to detect potential safety issues associated with approved vaccines. But anyone can submit VAERS reports, and they are not all independently verified.

“Note that the inclusion of events in VAERS data does not imply causality,” the VAERS website says. “Please note that VAERS staff follow-up on all serious and other selected adverse event reports to obtain additional medical, laboratory, and/or autopsy records to help understand the concern raised.”

VAERS reports have repeatedly been cited on social media to falsely claim Covid-19 vaccination is harmful. AFP Fact Check has debunked several of these claims here, here and here.

The CDC previously told AFP that VAERS “accepts all reports of adverse events after vaccination, without regard to whether or not the vaccine caused the event.” The agency maintains an updated list of adverse events associated with the vaccine.

Autoimmune blistering disease unrelated to monkeypox, vaccines

Health experts told AFP it is also incorrect to link autoimmune blistering diseases to monkeypox and the Covid-19 vaccines, as Down the Chupacabra Hole does in its blog post.

“There is no scientific basis for believing that the Covid-19 vaccine can cause monkeypox or that monkeypox is the same thing as autoimmune blistering disease,” Debbink said.

Verardi said skin lesions can have many different causes, including plants, autoimmune diseases and viruses such as monkeypox. But he confirmed that monkeypox is “completely unrelated to autoimmune blistering disease,” as are the Covid-19 vaccines.

“Vaccines of all types (including the Covid-19 vaccines) typically do not cause skin lesions,” he said. “If and when autoimmune blistering disease occurs after vaccination, it is 1) very rare, 2) still likely unrelated to the vaccination (no causal relationship), and 3) certainly unrelated to monkeypox.”

Other posts on social media have falsely conflated monkeypox with shingles, a distinct virus.

Isaac Bogoch, an infectious diseases professor at the University of Toronto, told AFP that “there may be some overlap in their clinical presentation,” but “monkeypox and shingles are two completely different infections.”

According to the CDC, the monkeypox virus comes from the Orthopoxvirus genus, which also includes the variola virus that causes smallpox. On the other hand, shingles is caused by the varicella-zoster virus, which also causes chickenpox.