A pair of studies released over the weekend indicate the epicenter of the COVID-19 pandemic was a large market in the Chinese city of Wuhan that sold live animals, countering persistent theories that the virus emerged from a nearby Chinese lab.

One of the studies found that two early lineages of the coronavirus have a “clear association” with the Huanan Seafood Market and noted that “beyond the Huanan market, no other proposed or hypothesized origin narrative has been supported by any data.”

The other study found at least two instances where the virus spilled over from another species to humans with the first occurring in late November or early December 2019, concluding that COVID-19 “emergence likely resulted from multiple zoonotic events.”

The studies didn’t offer definitive conclusions as to what animal species hosted the virus before spreading it to humans, but one suggested that raccoon dogs were previously sold in an area of the market where several coronavirus-positive environmental samples were taken.

Cartoons on the Coronavirus

Neither study has been peer reviewed.

Maria Van Kerkhove of the World Health Organization said of the research that “many more studies are needed” and said that finding the first human cases of a new disease is “extremely difficult, if not impossible.”

“The Huanan market indeed played a very important role in this pandemic, but I would urge further studies continue to be needed … to trace back animals sold there prior to the first detected cases,” Van Kerkhove tweeted.

WHO has also been investigating the origin of the coronavirus and released a study last year concluding that the most likely route the virus took to infect humans involved an infected intermediate animal host. It said the lab-leak theory of the origin of the virus was an “extremely unlikely pathway.”

But the organization noted that its international team of experts was not given access to all of the data they wanted surrounding their trip to Wuhan to study the origin of the coronavirus. Specifically, the team did not have full access to biological samples from September 2019 that could help them understand the earliest cases of COVID-19.

By Percy