Wuhan scientists initially worried about coronavirus leak from lab

After a month-long investigation in Wuhan, the World Health Organization has offered the most comprehensive analysis to date on the origin of the coronavirus and how it could have entered the human population.

The WHO report, released Tuesday, lists the scenarios of possible origin of the coronavirus in order of probability. At the top is the possibility that the coronavirus has passed from bats to humans via an intermediate animal host, possibly at a wildlife farm in China. Last in the rankings is the controversial theory that the virus leaked from a Chinese laboratory.

But at a press conference on Tuesday, WHO Director-General Tedros Adhanom Ghebreyesus said he “did not think this assessment was in depth enough.”

“Although the team concluded that a lab leak is the least likely hypothesis, it requires further investigation, possibly with additional missions involving specialist experts, which I am prepared to deploy,” he said. -he declares. Tedros added that members of the WHO international team who visited China “spoke of the difficulties they faced in accessing the raw data.”

Following the publication of the report, the United States and a dozen other countries called for an independent inquiry into the origins of the coronavirus – an inquiry that would be “free from interference and undue influence,” the Wall reported. Street Journal.

Laboratory leak ‘extremely unlikely’, but WHO has not audited Wuhan laboratories

Tedros said the laboratory leak hypothesis should “remain on the table” because WHO experts have only spent hours in every high-level biosafety lab in Wuhan.

Peter Ben Embarek, a WHO animal disease scientist, told the press conference that the group had not done “a full investigation or audit” of a particular laboratory. Overall, he added, the possibility of a laboratory leak “has not received the same depth of attention and work” as other hypotheses about the origin of the virus.

Still, the report offers compelling reasons why the virus is extremely unlikely to have escaped from a lab.

The team found no evidence that samples of the novel coronavirus existed at the Wuhan Institute of Virology, where scientists were studying various coronaviruses before the pandemic, before the first cases of COVID-19 were reported in December 2019. .

The WHO also found no records indicating that viruses closely related to the novel coronavirus were kept in a Chinese laboratory before this month. There was also no virus that, when combined, could have produced the new coronavirus.

Hector Retamal / AFP via Getty

Additionally, no staff at Wuhan labs studying coronaviruses reported cases of respiratory illness “in the weeks / months leading up to December 2019,” the report said.

Staff blood samples during this time (which are regularly taken from biosafety lab workers to monitor their health) have also all tested negative for anti-coronavirus antibodies. This suggests that no lab worker was infected before the pandemic.

“It’s something that comes out of our laboratories”

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The WHO team report, however, found that the Wuhan Institute of Virology (WIV) had moved to a new location in early December 2019. The new facility was about 8 miles from the wholesale market in Huanan Seafood, to which the first cluster of cases was linked.

This proximity, coupled with the fact that there were several labs in Wuhan studying coronaviruses when the pandemic started, has led to speculation about a possible link between a lab and the market outbreak.

“Even the staff at those labs told us that was their first reaction when they heard about this new emerging disease, this coronavirus: ‘This is something coming out of our labs,’” Embarek said.

“They all went back to their files and worked to try to find out if there was a link but no one could find a trace of anything similar to this virus in their files or their samples,” he said. -he adds.

But the Embarek team did not have the resources to fully verify this claim.

“A team of scientists is not qualified to perform a detailed audit of WIV records, or access institutional files, lab notebooks, databases or freezer inventories,” virologist Angela Rasmussen told Science. , virologist and member of the WHO team.

By Han Guan / AP

Dominic Dwyer, a WHO microbiologist who has previously worked in high-level biosafety labs, said on Tuesday that the team was “convinced there was no clear evidence of a problem,” in any laboratories visited. He also noted that a full forensic examination of a lab is a complex process and that it was “not what we were there to do.”

However, the WHO team spoke with laboratory managers and staff about their safety protocol and confirmed that the facilities were well managed.

There is ample evidence to conclude that bats first transmitted the coronavirus to an animal, WHO experts have said. Then this animal population transmitted it to humans. Indeed, a May study found that the new coronavirus shared 97.1% of its genetic code with a coronavirus called RmYN02, which was found in bats in China’s Yunnan province between May and October 2019.

Bats are common virus hosts – the interspecific hops of bat populations have also led to outbreaks of Ebola, SARS, and Nipah virus.