New research says the Wuhan market is the only “probable” source of the COVID-19 pandemic.

Shortly after the World Health Organization and China released a report last year dismissing the possibility that the SARS-CoV-2 virus originated from a laboratory leak, scientists from major research institutes around the world noted the paucity of published data and spoke out. for thorough scientific research into the origin of the pandemic.

An international panel of experts responded to the protest on Tuesday with two additional papers published in the journal Science. Using different analytical approaches, both articles identify the Huanan Seafood Wholesale Market in Wuhan as the epicenter of the pandemic that has since killed more than 6.4 million people World.

Although the exact species of the animal is not yet known, the authors conclude that SARS-CoV-2 was most likely present in animals sold on the market in late 2019, and on at least two separate occasions was infected by humans or customers.

“In a city of over 3,000 square miles, the area most likely to contain the home of a person who had one of the earliest cases of COVID-19 in the world is an area a few city blocks from the Huanan area. market slap inside it”, Michael Sparrowa virologist at the University of Arizona who co-authored one of the new studies, the statement said.

“All these data tell us the same thing: they point directly to this particular market in the center of Wuhan,” echoes the co-author of the study. Christian Andersen Scripps Research Institute in San Diego.

“Any other version — like a leak from a lab — would have to explain all of this other evidence, and in my opinion,” he added, “it’s just not plausible.”

In the early days of the pandemic, before SARS-CoV-2 spread widely in the US, Andersen wrote to Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, expressed concern that the new virus has features that are common to humans.

As his research progressed, so did his thinking.

“I myself was quite convinced of the lab leak until we dived into it very carefully and looked at it much closer,” Andersen said. “In fact, the data points to this particular market.”

Sparrow also doubted the origin story of Huanan Market. He was one of 18 experts who published open letter last year in the journal Science that called for a more thorough investigation into the possibility that the virus inadvertently escaped from the research lab.

“I didn’t see any evidence that I could look at and say, ‘Oh, okay, that certainly disproves the random laboratory origin and gives almost 100% certainty that it was a natural phenomenon,'” he said at the time. . “As long as we’re not at the stage, both possibilities are viable.”

Sparrow continued to hold detailed records of the earliest cases or what was then thought to be pneumonia of unknown origin. Have reported in science that the 41-year-old accountant who was marked as the first patient with COVID-19 on December 1st. 8 did have a fever due to dental surgery. The accountant appeared to have contracted the coronavirus eight days later, but that was after a few days. seafood vendor from huanan market was looking for treatment for what was likely COVID-19.

The teams behind the new research consisted of more than 30 researchers from 20 different institutions around the world. They divided their work into two parts: one tracked the initial emergence of the virus in animals and humans, and the other analyzed genomic data from the earliest cases.

AT first study, the team was able to analyze the location of nearly all of the COVID-19 cases identified by the WHO in December 2019, 155 of which were in Wuhan. All of the sickest patients in the first month of the outbreak were centered around the market.

By January and February, as the virus spread, the highest concentrations of infections had moved from the area surrounding the market to the most densely populated areas of the city.

In addition, swabs taken from surfaces at the market itself were significantly more likely to test positive from cages and stalls selling live animals vulnerable to the coronavirus, including red foxes and raccoon dogs. These animals were likely infected from bats or other farm animals known to carry the coronavirus.

second study reviewed the genomic sequence of the virus in the early days of the pandemic. Researchers have identified two distinct transmission lines for SARS-CoV-2, suggesting that the virus entered the human population on two separate occasions.

“Before embarking on this research, it was very unclear to us how bloodline A and bloodline B are related to each other, and whether they both originated in or around the Huanan Market,” he said. Dr. Mark Suchar, a biostatistician at the UCLA Fielding School who worked on the study. The data showed that both versions of the virus were circulating on the market, suggesting that there were at least two separate cases of successful animal-to-human transmission of the virus. “You’re about 60 times more likely to have multiple submissions,” Suchard said.

The studies are an indirect response of the WHO commission. report on the origin of the pandemic, published in March 2021. Using data provided by China, the report ranked four possible scenarios pandemic genesis from “highly unlikely” to “very likely”.

In this report, the most likely cause of the pandemic was the transmission of the virus from the host species to humans through an intermediary animal. An accidental release of the virus from the Wuhan Institute of Virology or another laboratory was considered the least likely.

Two other theories studied included direct animal-to-human transmission (“possible to probable”) and surface transmission from frozen foods (“possible”).

Almost immediately after the publication of the report, scientists around the world expressed concern. In May 2021, the journal Science published an open letter from Sparrow and researchers at Harvard, Yale, Stanford and other leading institutions calling for a more thorough investigation.

They argued that the report’s findings did not seem implausible. The problem, the scholars wrote, was that the report did not appear to have sufficient evidence to support any conclusion.

“For all intents and purposes, this was not an adequate, detailed presentation of the data that would allow an outside scientist to reach an independent conclusion.” Dr. David Relmanthe co-author of the letter and professor of microbiology and immunology at Stanford University told The Times when the letter was published.

WHO Director General Tedros Adhanom Ghebreyesus It seems that after the release of the report, they shared similar concerns, offering the resources of a global organization to conduct a more thorough investigation.

“While the team concluded that the lab leak was the least likely hypothesis, this warrants further study,” he said in an interview. speech member states. “Let me be clear that, as far as WHO is concerned, all hypotheses remain on the table.”

BUT follow-up report published last month by a group of experts convened by the WHO said that more work needs to be done to understand whether the pandemic could have been caused by a laboratory accident.

Andersen warned that hard evidence is harder to find in biology than in fields like mathematics or physics. However, he and his fellow co-authors, who have previously considered the lab leak hypothesis, said they think the evidence currently available points strongly in one direction.

Sparrow agreed. The evidence he and his colleagues released on Tuesday, he said, “led me to the point that I now also think it’s just not plausible that this virus was introduced in any other way than through the wildlife trade in the market. Huanan.