International scientists who examined previously unavailable genetic data from samples collected near the market that detected the first human cases of COVID-19 in China say they have found evidence suggesting the pandemic originated in animals. not from the laboratory.
Other experts have yet to verify his analysis, which has not yet appeared in a peer-reviewed journal. How the coronavirus first started making people sick remains uncertain.
“These data do not provide a definitive answer as to how the pandemic started, but every piece of data is important to move us closer to that answer,” WHO Director-General Tedros Adhanom Ghebreyesus told a Friday press briefing.
He also criticized China for not sharing genetic information earlier, saying “this data could and should have been shared three years ago.”
Samples were collected from surfaces at the Huanan Seafood Market in Wuhan after the first human cases of COVID-19 were detected in late 2019.
Tedros said the genetic sequence was uploaded to the world’s largest public virus database by scientists at the Chinese Center for Disease Control and Prevention in late January; The data has since been removed from the database.
A French biologist scouring the database stumbled upon the information and shared it with a group of scientists based outside China and looked into the origins of the coronavirus.
According to the scientists, genetic sequencing data showed that some samples, which were believed to be positive for the coronavirus, also contained genetic material from raccoon dogs, indicating that the animals may have been infected with the virus. Their analysis was first reported in The Atlantic.
“There’s a good chance that the animals that deposited the DNA also deposited the virus,” said Stephen Goldstein, a virologist at the University of Utah who analyzed the data. “If you were going to do environmental sampling after a zoonotic spillover event … this is basically what you would expect to find.”
Ray Yip, an epidemiologist and founding member of the US Centers for Disease Control Office in China, said that even though the new findings were not definitive, they were important.
“The market environmental sampling data published by the China CDC is the strongest evidence to date to support an animal origin,” Yip told the AP in an email. He was not associated with the new analysis.
Scientists have been searching for the origins of the COVID-19 pandemic since the virus first emerged, but the search has been complicated by factors including a sharp increase in human infections in the first two years of the pandemic and increasingly political controversy.
It took virus experts more than a dozen years to pinpoint the animal origin of the related virus SARS.
The researchers say their analysis is the first solid indication that the market may contain wildlife infected with the coronavirus. Goldstein said some samples containing raccoon dog DNA were collected from a stallion that had tested positive for Covid-19 and was known to be involved in the wildlife trade.
But it is also possible that humans first introduced the virus to the market and infected raccoon dogs, or that infected humans left traces of the virus with the animals.
After the group’s scientists contacted the China CDC, he says, the sequences were pulled from a global virus database. The researchers are perplexed as to why the data from the samples collected three years ago was not made public sooner.
Earlier this week, some scientists presented their findings to an advisory group that the World Health Organization has tasked with investigating the origins of Covid, Goldstein confirmed.
Mark Woolhouse, an infectious disease specialist at the University of Edinburgh, said it would be important to see how the genetic sequences of raccoon dogs match up with what is known about the historical evolution of the COVID-19 virus.
He added that if the analysis shows that animal viruses are of earlier origin than those infecting people, “that’s probably as good evidence as we can hope that this was a spillover event in the market.” “
After a week-long trip to China to study the origins of the pandemic, the WHO released a report in 2021 concluding that COVID probably jumped from animals to humans, making the possibility of a laboratory origin “highly improbable”. Rejected by saying
But the UN health agency backtracked the following year, saying “key pieces of data” were still missing.
In recent months, WHO director Tedros has said all hypotheses remain on the table, while he and senior officials urged China to share more data about their COVID-19 research.
China CDC scientists who analyzed the first samples published a paper as a preprint in February. Their analysis suggested that humans brought the virus to market, not animals, meaning the virus originated elsewhere.
The paper did not mention that animal genetic material was found in samples that tested positive for Covid-19, and the authors did not upload the raw data until March. Gao Fu, former head of the China CDC and lead author of the paper, did not immediately respond to an email requesting comment.
Wuhan, the Chinese city where Covid-19 was first detected, is home to several laboratories involved in collecting and studying coronaviruses, the theory that the virus may have leaked from one.
In February, the Wall Street Journal reported that the US Department of Energy had assessed “with low confidence” that the virus had leaked from a laboratory. But others in the US intelligence community disagree, believing it first came from animals. Experts say the true origins of the pandemic may not be known for many years – if ever.