In its first report, a team of international scientists assembled by the World Health Organization to advise on the origin of the coronavirus said on Thursday that bats likely carried an ancestor of the coronavirus that then turned into a mammal that entered a market for wild animals. animals are sold. † But the team said more Chinese data was needed to study how the virus spread among humans, including the possibility that a lab leak played a role.
The team, appointed by WHO in October as the organization sought to review its approach to studying the origins of the pandemic, said Chinese scientists had shared information with them on two occasions, including from unpublished studies. But gaps in Chinese reports made it difficult to determine when and where the outbreak occurred, the report said.
Independent experts said it was unclear how the team, made up of scientists from the United States, China and two dozen other countries, could help the WHO break through political barriers in China that prevent the publication of most of the information leading to the rise of the virus. virus would have slowed down. the national borders.
“China’s lack of political cooperation continues to hinder any meaningful progress,” said Lawrence Gostin, who directs the O’Neill Institute for National and Global Health Law at Georgetown University. He said the report provided a roadmap for investigating future pandemics in less secretive countries.
The WHO asked the group for advice not only on studying the origins of the coronavirus, but also on examining the emergence of future pathogens. The team, known as the Scientific Advisory Group for the Origins of Novel Pathogens, has no authority to conduct research in China or elsewhere.
Maria Van Kerkhove, WHO’s Covid-19 technical leader, said the report was “just the beginning of their work”.
The group was expected to show more openness to a lab leak than a previous team the WHO sent to China in early 2021. That earlier team’s joint report with China said a lab leak, while possible, was “extremely unlikely.” WHO Director-General Tedros Adhanom Ghebreyesus called the assessment premature.
The latest report said there was no new data pointing to a lab leak. But leaders of the group said they wanted to evaluate any evidence that emerges in the future.
“We have not received any reports that really indicate there is a lab leak that we believe needs to be closely monitored,” said Marietjie Venter, the team’s chair and a professor of medical virology at the University of Pretoria in South Africa.
Attempts to study a lab leak met resistance from team members from China, Russia and Brazil, who failed to see the need for such an investigation, the report said.
The report cited a number of studies into the possible role of animals in the genesis of the coronavirus that had been published since the work of the previous WHO team. For example, a survey of a live animal market in Wuhan, China, found several species known to be susceptible to the coronavirus in the fall of 2019.
When people associated with that market started getting sick, police closed down and disinfected the facility, making it more difficult for scientists to identify potential intermediate hosts for the virus.
The latest report said it focused on published, peer-reviewed studies, though it acknowledged some unpublished studies posted online as “pre-prints.” Among them were two papers released this year in which a team of scientists argued that the pandemic started when a bat infected a wild animal, such as a raccoon dog, which was then sold at the Huanan Seafood Wholesale. Market in Wuhan.
Michael Worobey, an evolutionary biologist at the University of Arizona who helped conduct those studies, said it was unfortunate that the WHO team didn’t look closely at the unpublished research.
“I think if you read our pre-prints and understand the evidence,” he said, “there’s actually really strong evidence that the pandemic was caused by wildlife in the Huanan market.”
dr. Worobey and other researchers said January 2020 missed an important opportunity to focus the search for the coronavirus on wildlife farms that supplied markets like Huanan. Millions of animals were reportedly killed instead.
Filippa Lentzos, a biosecurity researcher at King’s College London, praised the latest report for noting that there are no published findings from China’s own origin studies. But she said her proposals for future investigations into the origins of pandemics did not adequately address investigations into “accidental or intentional events,” which she said would require expertise outside of public health.
Jesse Bloom, a virologist at the Fred Hutchinson Cancer Research Center, said the report made it clear that to mitigate future pandemic threats, both animal and laboratory origins must be considered.
“Both things are enough serious possibilities to think about together,” he said.
The report recommended studies of blood samples from workers in wildlife farms and live animal markets and of genomic data from early viral samples. But the previous WHO team had suggested some similar studies, but to no avail.
The latest report stated that Dr. Tedros twice wrote to Chinese officials in February asking for information on the status of those investigations and for information about a possible lab leak. But there was no evidence that the WHO could convince China to share the results of such work.
Despite the difficulties, however, some information has seeped out from China.
Last week, Chinese researchers published a small study on raccoon dogs and bats collected in the Wuhan region in January 2020. In 15 raccoon dogs, the researchers found a new strain of coronavirus related to a species that infects dogs. In 334 bats, the researchers found coronaviruses that appear to be a mix of viruses, some related to the one that caused Covid and others related to the one that caused SARS in 2003.
“This sample size is not large enough,” said Maciej Boni, a virologist at Penn State University. “We need samples on the scale of tens of thousands of bats to get a complete picture.”