There’s a tantalizing new clue in the hunt for the origins of the Covid-19 pandemic.The new analysis of genetic material collected from January to March 2020 at the Huanan Seafood Market in Wuhan, China, has uncovered animal DNA in samples already known to be positive for SARS-CoV-2, the coronavirus that causes Covid-19.
A significant amount of that DNA appears to belong to animals known as raccoon dogs, which were known to be traded at the market, according to officials with the World Health Organization, who addressed the new evidence in a news briefing on Friday.
The connection to raccoon dogs came to light after Chinese researchers shared raw genetic sequences taken from swabbed specimens collected at the market early in the pandemic. The sequences were uploaded in late January 2023, to the data sharing site GISAID, but have recently been removed.
An international team of researchers noticed them and downloaded them for further study, the WHO officials said Friday.
The new findings – which have not yet been publicly posted – do not settle the question of how the pandemic started. They do not prove that raccoon dogs were infected with SARS-CoV-2, nor do they prove that raccoon dogs were the animals that first infected people.
But because viruses don’t survive in the environment outside of their hosts for long, finding so much of the genetic material from the virus intermingled with genetic material from raccoon dogs is highly suggestive that they could have been carriers, according to scientists who worked on the analysis. The analysis was led by Kristian Andersen, an immunologist and microbiologist at Scripps Research; Edward Holmes, a virologist at the University of Sydney; Michael Worobey, an evolutionary biologist at the University of Arizona. These three scientists, who have been digging into the origins of the pandemic, were interviewed by reporters for The Atlantic magazine. CNN has reached out to Andersen, Holmes and Worobey for comment.
The details of the international analysis were first reported Thursday by The Atlantic.
The new data is emerging as Republicans in Congress have opened investigations into the pandemic’s origin. Previous studies provided evidence that the virus likely emerged naturally in market, but could not point to a specific origin. Some US agencies, including a recent US Department of Energy assessment, say the pandemic likely resulted from a lab leak in Wuhan.
What the samples show
In the news briefing on Friday, WHO Director-General Tedros Adhanom Ghebreyesus said the organization was first made aware of the sequences on Sunday.
“As soon as we became aware of this data, we contacted the Chinese CDC and urged them to share it with WHO and the international scientific community so it can be analyzed,” Tedros said.
