Why the Wuhan lab-leak origin theory of the COVID-19 virus is being taken more seriously

18 scientists signed letter calling for inquiry into COVID-19 origin

Posted: May 28, 2021
Last Updated: July 22, 2021

Security personnel keep watch outside the Wuhan Institute of Virology during the visit by the World Health Organization (WHO) team tasked with investigating the origins of COVID-19, in Wuhan, Hubei province, China on Feb. 3, 2021. (Thomas Peter/Reuters)

For Canadian biotech entrepreneur Yuri Deigin, whose 16,000-word essay last April provided one of the first detailed arguments that the COVID-19 virus could have escaped from a Chinese lab, the recent traction gained by such a theory provides a measure of satisfaction.

"When I just put it out, I was ridiculed and attacked as a crackpot, a crazy guy who doesn't know what he's talking about," Deigin said from Moscow. 

During the pandemic, Deigin has been independently researching the origins of the virus online and sharing information on social media with a loosely formed group of self-proclaimed "Twitter detectives."


He says he, too, initially believed what appeared to be the general scientific consensus, that the virus behind COVID-19 originated naturally through human contact with an infected animal in Wuhan, China, "because that's how viral outbreaks usually happen."  

But, Deigin said, after he delved into the competing theory, "it became very clear that this is not a crazy hypothesis, not a crazy conspiracy theory."

To be clear, the so-called Wuhan lab-leak theory isn't back in the news because any major piece of evidence has been uncovered to give it credence. What has changed is calls from scientists in the field, the Biden administration, and others to investigate it properly — because even the head of the World Health Organization says that hasn't happened yet.

"I have to remind everybody and myself, too, that, you know, we're still far from a conclusive proof either way," said Deigin.

'Do a serious investigation'

The lab-leak theory postulates that researchers at the Wuhan Institute of Virology, which does work with coronaviruses, may have been studying or even modifying such viruses to better understand them, and that a lab accident may have allowed the virus to escape.

It was floated shortly after the pandemic emerged, and championed by then U.S. president Donald Trump and other Republicans, but dismissed by many as a conspiracy theory.


But, without clear evidence of a natural origin, or what scientists call "zoonotic spillover" from an animal host, the idea hasn't gone away.

"As time progresses, the fact that China doesn't allow any substantive investigation into the origins of it, people are going to naturally begin to wonder why,"  said Dr. Peter Hotez, dean of the National School of Tropical Medicine at the Baylor College of Medicine.

"And so then any time a new snippet of evidence comes along that that seems odd ... people are more and more prone to jump to that conclusion that either it had human origins or it was the lab."

(Thomas Peter/Reuters)

While Hotez still thinks a natural origin is most likely, he says a lab accident or more human involvement can't be dismissed entirely with the evidence at hand.

"But the only way to resolve this: Do a serious investigation."


On Wednesday, U.S.  President Joe Biden ordered U.S. intelligence officials to "redouble" their efforts to investigate the origins of the COVID-19 pandemic, including any possibility the trail might lead to a Chinese laboratory.

Add to that, a number of articles, including two published essays from former New York Times science writers Donald G McNeil Jr. and Nicholas Wade, postulated the lab-leak theory. The Washington Post's fact checker Glenn Kessler  laid out a timeline under the headline: How the Wuhan lab-leak theory for pandemic origin suddenly became credible. 

Meanwhile, the  Wall Street Journal reported this week that three researchers from the Wuhan Institute of Virology sought hospital care in November 2019, a month before China reported the first cases of COVID-19.

But perhaps the biggest  catalyst for another look at the virus's origins came earlier this month, with  a letter published in Science, signed by 18 scientists, asking for a "proper investigation" into the origins of COVID-19, and criticizing the report released in March by investigators of the World Health Organization.

Lab incident 'extremely unlikely': WHO report

That report, which was subsequently criticized by the U.S., Canada and other governments for the lack of access granted to the investigators, determined that it was  "likely to very likely," the coronavirus had a zoonotic source and that a laboratory incident was "extremely unlikely."


"The two theories were not given balanced consideration," the scientists wrote in their letter. "Only four of the 313 pages of the report and its annexes addressed the possibility of a laboratory accident."

"We must take hypotheses about both natural and laboratory spillovers seriously until we have sufficient data."

(The Associated Press)

Akiko Iwasaki, a professor of immunobiology at the Yale School of Medicine and one of the signatories of the letter, said she doesn't have an opinion one way or the other about the origin of the virus, but that the conclusions reached by the WHO investigation were problematic. 

"Even though there is very little evidence for any of these possibilities, that report basically said that the lab is extremely unlikely. Whereas the other possibilities are possible to likely," she said.

"So as a scientist, it feels a bit awkward without any data to conclude the likeliness of these scenarios in this manner."


Let me say clearly that as far as WHO is concerned all hypotheses remain on the table. - WHO Director-General Dr. Tedros Adhanom Ghebreyesus

Dr. David Fisman, an epidemiologist at the University of Toronto's Dalla Lana School of Public Health and the only Canadian scientist to sign the letter, believes the inadequate WHO investigation was a milestone for changing attitudes toward the lab-leak theory.

"[It] was framed in such an unreasonable way," he said. "Putting out a 300 page report on the origins of the virus that can't conclude anything except that it concludes very firmly that it didn't come from the lab — that's the lady doth protest too much."

Even as the report was released, WHO Director-General Dr. Tedros Adhanom Ghebreyesus also expressed concerns about the investigation, that the assessment was not  "extensive enough" and that "further data and studies will be needed to reach more robust conclusions."

"Let me say clearly that as far as WHO is concerned all hypotheses remain on the table."

WATCH | Biden calls for investigation into COVID-19 origins:

Show more
U.S. President Joe Biden ordered a new investigation into where the COVID-19 virus came from after renewed information it may have accidentally escaped from a lab in Wuhan, China.  2:00


What else has changed

Both Iwasaki and Fisman also believe that the evolution into more open discussions of the lab-leak theory as a viable explanation can be traced to the departure of Trump from the White House.

Any suggestion of a human origin became tarnished, for some, by Trump's peddling in unsubstantiated theories that fanned the flames of xenophobic attitudes toward China, they said.

"It was difficult for scientists to really discuss this in an open, rational manner," Iwasaki said. 

"You don't want to be seen to be contributing to the misinformation or to a toxic narrative that harms people," Fisman said. "So I think that kept folks pretty quiet."


  • This story has been updated to reflect that Yuri Deigin's theory about the origins of the coronavirus is based on information he independently compiled.

With files from The Associated Press