The long-standing debate about the origins of covid-19 took a new turn this week after a French scientist noticed that genetic sequences entered into a database by Chinese researchers suggest that those responsible for the coronavirus could have come from animals such as raccoon dogs in Huanan. Seafood market in Wuhan.

Within a few days, the sequences were removed by the same researchers, although some other scientists had downloaded them in advance and are conducting further research.

“It is very important that any data relating to how this pandemic began be made available immediately,” Maria van Kerkhove This was announced by the World Health Organization (WHO) at a press conference on March 17.

“There are several hypotheses that need to be explored, including how the virus entered the human population: from a bat, through an intermediate host, or through a biosecurity breach in the laboratory. And we don’t have a definitive answer.”

The Huanan market has long been considered a likely source of the SARS-CoV-2 coronavirus, as many of the first cases of covid-19 in December 2019 were in people associated with it, and the stalls sold a range of live and dead animals, not just seafood .

Bats are believed to be the original host of SARS-CoV-2, as they carry many coronaviruses, although SARS-CoV-2 has not yet been found in them. The ancestor of this virus may have passed from bats to a marketed intermediate host and then to humans.

An alternative explanation is that the virus escaped from the Wuhan Institute of Virology, where researchers are known to study bat coronaviruses but not SARS-CoV-2. While this is a less popular idea among scientists, the US Department of Energy said in February that this was the most likely explanation, but released no supporting evidence.

Now, genetic sequences uploaded by the Chinese Center for Disease Control and Prevention into a global virological database called GISAID may have shed more light on the origin of SARS-CoV-2. These sequences were obtained from swabs taken from various surfaces on the market in early 2020 after its closure.

They were noticed Florence Debarre at the French National Center for Scientific Research, which shared its findings with WHO on 14 March. “When I logged in, I focused on market sequences, but I didn’t expect to find the data that I found,” says Debarre.

Debarre refused to say anything else until her analysis was complete, but Van Kerkhove said at a press conference: “Among the samples that were positive for SARS-CoV-2, they saw evidence of animal DNA. Some of these animals include raccoon dogs.”

raccoon dogs (niktereutes procyonoides) have previously been found to be susceptible to and capable of spreading SARS-CoV-2. “We know they know how to wear it,” says Alice Hughes at the University of Hong Kong.

This does not prove that raccoon dogs or any other animals on the market were infected with the virus in December 2019, and such evidence is not available now, Hughes says.

Jonathan Stay of the Francis Crick Institute in London says: “The data appears to provide strong evidence that raccoon dogs and other animals were in the market at a critical time. This is another link in the chain that would be expected if the pandemic started in this way.”

In addition to the information Debarre shared, Van Kerkhove said the WHO has asked the Chinese Center for Disease Control and Prevention to re-release the genetic data. “The big problem is that this data exists and that it is not available to the international community, let alone that it should have been available years ago.”