As the WHO states that all options “remain on the table,” scientists analyze another another hint regarding the Covid-19’s potential origins.
The search for the Covid-19 pandemic’s roots has a tantalizing new lead.
Animal DNA was found in samples previously known to be positive for SARS-CoV-2, the coronavirus that causes Covid-19, according to a new examination of genetic material gathered between January and March 2020 at the Huanan Seafood Market in Wuhan, China. In a news briefing on Friday, representatives from the World Health Organization discussed the new evidence and said that a sizable portion of that DNA appeared to belong to creatures known as raccoon dogs, which were known to be exchanged at the market.
Once Chinese researchers shared the raw genetic sequences obtained from samples swabbed at the market early in the pandemic, the link to raccoon dogs was discovered. Late in January 2023, the sequences were published to the data-sharing website GISAID, but they have since been taken down.
According to the WHO officials, they were discovered by an international team of experts who downloaded them for additional research.
The origin of the pandemic remains an open topic despite the latest findings, which have not yet been made public. They don’t demonstrate either that raccoon dogs were the first animals to infect humans with SARS-CoV-2 or that raccoon dogs were the ones to do it. Yet, since viruses can’t survive outside of their hosts for very long, the fact that so much of the virus’ genetic material coexisted with raccoon dogs’ genetic material strongly suggests that the latter might have been carriers, according to the researchers who carried out the examination. Kristian Andersen, an immunologist and microbiologist at Scripps Research, Edward Holmes, a virologist at the University of Sydney, and Michael Worobey, an evolutionary biologist at the University of Arizona, served as the analysis’s principal investigators. Reporters for The Atlantic magazine spoke with these three scientists, who have been researching the causes of the pandemic. For comment, CNN has contacted Andersen, Holmes, and Worobey.
The Atlantic broke the international analysis’s details first on Thursday.
The new information is becoming available as congressional Republicans launch inquiries into the cause of the pandemic. Although earlier research could not pinpoint the virus’s exact origin, it showed that it probably arose spontaneously in the market. The epidemic was probably caused by a lab leak in Wuhan, according to certain US authorities, including a recent US Department of Energy review.
What the examples reveal
WHO Director-General Tedros Adhanom Ghebreyesus said the organization learned about the sequences for the first time on Sunday during the news briefing on Friday.
As soon as we learned of this information, we called the Chinese CDC and requested them to share it with WHO and the global scientific community so that it might be examined, according to Tedros.
The WHO also met on Tuesday to review the information with its Scientific Advisory Group on the Origins of the New Pathogens, or SAGO, which has been looking into the causes of the pandemic. Both the international team of experts and the Chinese scientists who had previously examined the sequences presented their findings to the gathering.
In the Friday briefing, WHO scientists stated that the data are not definitive. They are still unable to determine if the virus spread from a lab or if it organically spread from animals to people.
“These data do not provide a conclusive solution to the question of how the pandemic began, but every piece of data is essential in bringing us closer to that answer,” Tedros said.
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The sequences do demonstrate that China possesses additional information that may be relevant to the pandemic’s beginnings that it has not yet shared with the rest of the globe, according to WHO authorities.
According to Tedros, this information should have been made public three years ago. “We continue to urge China to share data transparently, to undertake the required inquiries, and to publish the findings.
Knowing how the pandemic started is still morally and scientifically necessary.
CNN has contacted the Chinese researchers who initially examined and shared the data, but has not heard back.
there are more data available
The Chinese experts shared their own study of the samples in 2022. They are associated with the Centers for Disease Control and Prevention in China. “No animal host of SARS-CoV2 can be deduced,” they wrote in the preprint report that was published last year. The study examined 457 animal samples and 923 environmental samples collected from the seafood market, and it discovered 63 environmental samples that tested positive for the virus that causes Covid-19. The majority came from the market’s western end. The Chinese authors reported in 2022 that none of the animal samples, which were taken from frozen and refrigerated food for sale as well as from live, stray animals roaming the market, were positive.
The Chinese academics found only a connection to humans among the various species of DNA present in the ambient samples, not any connections to other animals.
A significant amount of DNA from raccoon dogs, a small animal related to foxes, was discovered when an international team of researchers recently took a fresh look at the genetic material in the samples that were swabbed in and around the stalls of the market. This was done using the cutting-edge genetic technique known as metagenomics. The virus that causes Covid-19 can infect raccoon dogs, who have long been thought to be the virus’s primary animal hosts.
“What they discovered is molecular proof that animals were sold at that market,” they said. Although they discovered molecular proof of it, that was suspected. Raccoon dogs were among the animals that were there that were susceptible to SARS-CoV2 infection, according to Maria Van Kerkhove, WHO’s technical lead for Covid-19, in a briefing on Friday.
This doesn’t alter the way we plan to research Covid-19’s genesis. It merely indicates that there is more data available, and that data must be fully shared, she added.
Van Kerkhove stated that “all possibilities remain on the table” until the global scientific community is able to analyze further information. Further proof of a natural genesis do you have?
The new evidence of a market genesis was deemed to be persuasive by some specialists, if not entirely so. The data does hint even more strongly toward a market origin, Andersen, an evolutionary biologist with Scripps Research who attended the WHO meeting and is one of the researchers looking at the new data, told the magazine Science.
The claims made on the new data instantly generated discussion within the scientific community.
The fact that the new analysis had not yet been made available for experts to review but had instead surfaced in press accounts, according to Francois Balloux, director of the Genetics Institute at University College London, called for caution.
The debate only becomes more polarized as a result of such pieces, according to a thread Balloux started on Twitter. “Those who are certain that it has a zoonotic origin would take it as conclusive evidence for their conclusion, and those who are certain that it was a lab leak will interpret the inadequacy of the evidence as attempts at a cover-up,” said the author.
The information, according to other specialists who were not part in the investigation, could be crucial in demonstrating the virus’s natural origin.
An analysis of all information relevant to the various origin-theory hypotheses was just released by Felicia Goodrum, an immunobiologist at the University of Arizona.
The virus that causes Covid-19 must be isolated from an animal that was on the market in 2019. According to Goodrum, this would be the best evidence for a natural spillover.
“Obviously, that is not conceivable, as neither sequencing nor time travel allow us to travel back in time, and no creatures were present at the time sequences could be collected. Goodrum told CNN in an email, “To me, this is the next best thing.
According to Van Kerkhove, who provided the WHO briefing, the Chinese CDC researchers submitted the sequences to GISAID as they were revising their initial research. She mentioned that their initial paper is currently being modified and resubmitted for publication. The information from China’s CDC is being updated and expanded, GISAID has informed us, she said.
Van Kerkhove stated on Friday that the WHO would like to be able to determine the origin of the animals. Were they crazy? A farm was used to raise them.
She claimed that as part of its inquiry into the pandemic’s beginnings, WHO had repeatedly requested studies from China that would allow it to track the animals back to their original farms. According to her, WHO also requested blood tests on market employees and tests on animals that may have originated from farms.
The WHO’s health emergency program executive director, Dr. Mike Ryan, urged experts worldwide who might have pertinent data to “share the data” on Friday. We will discover the solutions if we let science do the work.
