There’s no evidence that the virus behind the monkeypox outbreak was leaked from a Wuhan lab

As countries that rarely see cases of monkeypox struggle to contain an ongoing outbreak, some social media users have promoted what feels like an oddly familiar theory: The monkeypox virus emerged from a lab in Wuhan, China.

Social media users such as comedian Jimmy Dore, who has spread health-related misinformation in the past, suggested such a connection.

"Woah. The NIH in the United States and the Wuhan viral institute were also working on monkeypox, and now there’s a monkeypox outbreak," Dore said in a video shared on Facebook. "What are the odds of that? I’m going to say 50-50. Whenever there’s a new outbreak now, 50-50 chance it was started in a Wuhan lab funded by Dr. Fauci and the NIH."

Dore’s co-host, comedian Kurt Metzger, responded: "I mean, not even a different virology lab accident? The same one?"

The post was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.)

First, there is no evidence that the monkeypox outbreak that led the World Health Organization on July 23 to declare it a "public health emergency of international concern" has any link to a lab accident in China.   

This misleading notion hearkens back to unproven theories about the COVID-19 pandemic. Since the early days of the pandemic, some have claimed that SARS-CoV-2, the coronavirus responsible for COVID-19, might have leaked from the Wuhan Institute of Virology. Although the exact origin of the virus behind COVID-19 is still unknown, a growing body of research suggests it emerged naturally from a Wuhan market. Some researchers are investigating the coronavirus lab-leak theory as a possibility.

The Wuhan Institute of Virology has been engaged in research related to monkeypox, but the suggestion that this work and the current monkeypox outbreak are tied has no basis in reality.

Experts told PolitiFact there’s no evidence that the virus that led to the current monkeypox outbreak came from a lab in Wuhan, China. Rather, they said the virus can be traced to an existing outbreak in West Africa.

Monkeypox is a zoonotic disease, meaning it is transmitted from animals to humans, said David Robertson, head of viral genomics and bioinformatics at the Medical Research Council-University of Glasgow’s Centre for Virus Research. The disease is caused by the monkeypox virus, also referred to as MPXV.

"The current international cases are all representing human-to-human transmission of MPXV and are linked to an ongoing West Africa outbreak," he said. 

In May, scientists in Portugal wrote on the forum Virological that early analysis of the virus’s genetic material "indicates that the 2022 virus belongs to the West African clade." (A clade is a group of organisms descended from a common ancestor.) They also found that the virus responsible for the outbreak "is most closely related to viruses associated with the exportation of monkeypox virus from Nigeria to several countries in 2018 and 2019, namely the United Kingdom, Israel and Singapore."

Mark Slifka, a professor of molecular microbiology and immunology at Oregon Health and Science University’s School of Medicine, said that the virus has been sequenced and linked to the West African clade.

"Based on these genetics, it likely originated from this region of Africa," Slifka said. "There is no evidence to suggest that the virus circulating internationally escaped from any lab."

Robertson agreed: "There’s no evidence, none, that the MPXV variant causing the recents cases was generated in a lab." 

In contrast, he said there is "strong evidence" the virus had been circulating in West Africa for years.

Monkeypox was indeed studied by Wuhan Institute of Virology researchers. 

"Experiments on PCR testing of monkeypox viruses have taken place in Wuhan," reported Deutsche Welle, a German media outlet, in a fact-check. "This is undisputed." The story linked to a study that was first published online in February 2022. 

The nine scientists who authored that study listed an affiliation with the Wuhan Institute of Virology, and four noted an additional affiliation with the University of the Chinese Academy of Sciences. The research focused on assembling a fragment of the monkeypox virus genome that could be used as a template for PCR testing, which the scientists described as "the gold standard" for the detection of viruses classified as orthopoxvirus, of which monkeypox is one. 

Experts said laboratory work with the monkeypox virus is usually highly regulated, with strict protocols that minimize the risk of accidental infection.

Labs "pose an extremely low risk, in fact, for the emergence of new viruses," said Robertson of the Centre for Virus Research. "Nature, on the other hand, is a very high risk and a constant source of new viruses."

He said viruses have frequently emerged naturally and will continue to emerge naturally. 

"With our highly interconnected world, we need to get much better at controlling local outbreaks before they become international events," Robertson said.

RELATED: Debating the origins of the COVID-19 virus: What we know, what we don’t know

RELATED: Monkeypox outbreak: What to know about its spread, symptoms and vaccines