An international team of World Health Organization (WHO) researchers said on Tuesday that the novel coronavirus SARS-CoV-2 most likely originated in animals before spreading to humans and dismissed the notion that it was the product of a lab accident in Wuhan.
Speaking at a press conference in Wuhan, members of the joint WHO/China investigative mission gave a summary of their findings after 12 days of fieldwork. The trip came after a painstaking negotiation process between the WHO and Beijing, given the latter’s resistance to any international inquiries or efforts appearing to blame China for the pandemic. The team visited hospitals, laboratories, and seafood and meat markets in Wuhan—considered the original epicentre of the outbreak—and said that though their work did not dramatically alter their initial picture of what had transpired, they now had important details of the story.
The scientists said that they considered multiple hypotheses to understand the transmission of the virus into the human population. “All the work that has been done on the virus and trying to identify its origin continue to point toward a natural reservoir,” said Dr. Peter Ben Embarek, a food safety scientist with the WHO and chair of the investigative team.
After conducting multiple interviews with employees and examining the health audit processes of the Wuhan Institute of Virology, the team said that it was improbable that the virus leaked from the lab—a theory that has gained momentum in the United States (US) and elsewhere—adding that it was “very unlikely that anything could escape from such a place,” given the institute’s strong safety controls. “Therefore, [it] is not in the hypotheses that we will suggest for future studies,” the mission added.
As for the direct zoonotic transmission from an animal to a human, Dr. Embarek said that the topic was worthy of further investigation but noted that the most likely pathway was via an “intermediary species that was potentially closer to humans where the virus can adapt and circulate and then jump to humans.” Transmission directly from bats to humans or through the trade of frozen food products are also possibilities, Embarek said. However, he stated that it was not yet possible to pinpoint the animal host in question, noting that it was a “work in progress.”
Liang Wannian, head of the expert COVID panel at China’s National Health Commission added that though bats or pangolins are potential candidates, the virus samples from these species were not “sufficiently similar” to the coronavirus. However, he said that the susceptibility of minks and cats to the virus showed that there may be other animals that serve as reservoirs, though research remains inconclusive (for now) on that front.
The experts also said that their study showed “no indication” of the virus circulating in Wuhan before the first official cases were recorded in December 2019. Liang further noted that the virus appeared to have been spreading in other parts of the city than the Huanan Seafood Market—the site of an early cluster of cases in late 2019—so it remains possible that the virus originated elsewhere. To that end, WHO experts like Dr. Peter Daszak have suggested broadening the scope of the study to include all of South East Asia to truly understand the origins of the virus.
“We’ve done a lot of work in China and if you map that back it starts to point towards the border and we know that there is very little surveillance on the other side in the whole region of South East Asia,” he told the BBC. “China is a very big place and South East Asia is a very big place. The supply chains to the Huanan seafood market were extensive, they were coming in from other countries, they were coming in from various parts of China, so to really trace that back it’s going to take some work,” he added.
WHO Dismisses Theory of COVID-19 Leaking from Wuhan Lab
The joint WHO/China investigative mission said it was more likely that the virus originated in animals and then jumped to humans.
February 10, 2021
SOURCE: AP Photo/Ng Han Guan via INDIAN EXPRESS