Previously unknown data provide new clues about the origin of the corona

Previously inaccessible genetic data from China provide new clues about the possible origin of the corona pandemic. An evaluation of the material brings raccoon dogs into play at a market in Wuhan, China, as potential carriers of the corona virus, as reported by The Atlantic magazine. According to the Berlin virologist Christian Drosten, the results support the assumption of a natural origin of Sars-CoV-2. "The preliminary result strongly supports my assumption that it originated in raccoon dogs or other carnivores (flesh eaters) such as vibrating cats, which has been expressed since the beginning of the pandemic," Drosten told the German Press Agency (dpa) on Friday.

According to The Atlantic report, scientists had stumbled across previously unknown Chinese data on samples from Wuhan's Huanan Market, which has been linked to the first coronavirus outbreak. The genetic sequences were obtained from swabs taken at and near market stalls in January 2020 - i.e. at the beginning of the pandemic. A few days ago, researchers at the Chinese Center for Disease Control and Prevention (CDC) added them to the freely accessible "Gisaid" genome database, where they were discovered and analyzed almost by accident by scientists in Europe, North America and Australia.

According to “The Atlantic”, an evaluation led by US virus experts showed that several market samples that had tested positive for Sars-CoV-2 also contained animal genetic material – often from raccoon dogs, a fox relative commonly kept on fur farms. According to the report, the scientists conclude from the type of sampling, among other things, that a raccoon dog infected with the corona virus could have been in the affected areas.

The new findings are likely to rekindle the debate about the origin of the corona virus. Most recently, the discussion about a laboratory failure as a possible origin of the pandemic flared up again, starting in the USA. The relationship between the United States and China is currently heavily strained for various reasons. The virus expert Fabian Leendertz also described the discussion as “purely politically motivated”. The founding director of the Helmholtz Institute for One Health in Greifswald emphasized that the laboratory hypothesis is still the most improbable of all hypotheses.

The theory that the coronavirus spread from wild animals to humans traded at the Wuhan market in 2019 has been around since the pandemic began and is seen by the majority of experts as by far the most likely. One reason is the existing knowledge about the first Sars virus, in which there was also such a transition, explained Drosten. "Of course you have to take any theories about the origin of the virus seriously, but a natural origin from one of the animal groups mentioned was the most likely explanation from the start."

Analyzes repeatedly supported this assumption. For example, studies presented in the journal Science in the summer of 2022 found that the earliest cases of Covid-19 in Huanan Market were concentrated among vendors selling live animals and people shopping there.

However, the current evaluation does not bring security either. The fact that the virus and mammalian genetic material now analyzed was so intimately mixed - enough to be extracted from a single swab - is not perfect evidence, Emory University virologist Seema Lakdawala is quoted as saying in The Atlantic . It is an important step, but does not have the same value as if Sars-CoV-2 had been detected directly from a raccoon dog or in the virus sample from a mammal sold in Wuhan at the time of the outbreak.

The head of the World Health Organization (WHO), Tedros Adhanom Ghebreyesus, said on Friday: "These data do not give us a definitive answer as to how the pandemic started, but any information is important to get closer to that answer." According to Maria van Kerkhove, the data initially only proves that raccoon dogs were traded on the market. This had previously been assumed, but never confirmed.

Ghebreyesus criticized China's information policy. “This data could have been made available three years ago, and it should have been. We again call on China to be transparent by providing data and we call on China to conduct the necessary investigations and report the results.”

The material that was temporarily available on "Gisaid" has since been deleted by China - why, you have to ask the Chinese CDC, said van Kerkhove in Geneva. Drosten said that a comprehensive study by the scientists actually involved in examining the Chinese raw data would certainly follow soon. The Atlantic reported that the Chinese team's analysis had already been submitted to a specialist journal for review.

"It's a bit surprising that this data has only now been collected," noted Leendertz, who was involved in the WHO's search for the Sars-CoV-2 origin. Examining environmental samples for the genetic makeup of animals in the area in question is actually a routine procedure. “What is missing now is to look further back – are there still infected intermediate hosts? Where did the raccoon dogs (or other susceptible animals traded there) possibly get the virus from?”

Like mink, raccoon dogs are among the animal species that are easily infected with corona. However, the new results do not rule out the possibility that other animals in the Huanan market were carriers of the virus - or even the origin of the transmission to humans. The new results did not provide conclusive evidence, according to The Atlantic, but it was "like finding the prime suspect's DNA at the crime scene."

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