There’s a tantalizing new clue within the hunt for the origins of the Covid-19 pandemic.
A brand new evaluation of genetic materials collected from January to March 2020 on the Huanan Seafood Market in Wuhan, China, has uncovered animal DNA in samples already identified to be optimistic for SARS-CoV-2, the coronavirus that causes Covid-19. A big quantity of that DNA seems to belong to animals generally known as raccoon canines, which had been identified to be traded on the market, in response to officers with the World Well being Group, who addressed the brand new proof in a information briefing on Friday.
The connection to raccoon canines got here to gentle after Chinese language researchers shared uncooked genetic sequences taken from swabbed specimens collected on the market early within the pandemic. The sequences had been uploaded in late January 2023, to the info sharing web site GISAID, however have lately been eliminated.
A world group of researchers observed them and downloaded them for additional research, the WHO officers mentioned Friday.
The brand new findings – which haven’t but been publicly posted – don’t settle the query of how the pandemic began. They don’t show that raccoon canines had been contaminated with SARS-CoV-2, nor do they show that raccoon canines had been the animals that first contaminated folks.
However as a result of viruses don’t survive within the atmosphere exterior of their hosts for lengthy, discovering a lot of the genetic materials from the virus intermingled with genetic materials from raccoon canines is extremely suggestive that they may have been carriers, in response to scientists who labored on the evaluation. The evaluation was led by Kristian Andersen, an immunologist and microbiologist at Scripps Analysis; Edward Holmes, a virologist on the College of Sydney; Michael Worobey, an evolutionary biologist on the College of Arizona. These three scientists, who’ve been digging into the origins of the pandemic, had been interviewed by reporters for The Atlantic journal. CNN has reached out to Andersen, Holmes and Worobey for remark.
The small print of the worldwide evaluation had been first reported Thursday by The Atlantic.
The brand new knowledge is rising as Republicans in Congress have opened investigations into the pandemic’s origin. Earlier research offered proof that the virus seemingly emerged naturally in market, however couldn’t level to a particular origin. Some US businesses, together with a current US Division of Power evaluation, say the pandemic seemingly resulted from a lab leak in Wuhan.
Within the information briefing on Friday, WHO Director-Basic Tedros Adhanom Ghebreyesus mentioned the group was first made conscious of the sequences on Sunday.
“As quickly as we grew to become conscious of this knowledge, we contacted the Chinese language CDC and urged them to share it with WHO and the worldwide scientific group so it may be analyzed,” Tedros mentioned.
WHO additionally convened its Scientific Advisory Group for the Origins of the Novel Pathogens, generally known as SAGO, which has been investigating the roots of the pandemic, to debate the info on Tuesday. The group heard from Chinese language scientists who had initially studied the sequences, in addition to the group of worldwide scientists taking a contemporary have a look at them.
WHO specialists mentioned within the Friday briefing that the info usually are not conclusive. They nonetheless can’t say whether or not the virus leaked from a lab, or if it spilled over naturally from animals to people.
“These knowledge don’t present a definitive reply to the query of how the pandemic started, however every bit of information is vital in shifting us nearer to that reply,” Tedros mentioned.
What the sequences do show, WHO officers mentioned, is that China has extra knowledge which may relate to the origins of the pandemic that it has not but shared with the remainder of the world.
“This knowledge may have, and will have, been shared three years in the past,” Tedros mentioned. “We proceed to name on China to be clear in sharing knowledge and to conduct the mandatory investigations and share outcomes.
“Understanding how the pandemic started stays an ethical and scientific crucial.”
CNN has reached out to the Chinese language scientists who first analyzed and shared the info, however has not obtained a reply.
The Chinese language researchers, who’re affiliated with that nation’s Heart for Illness Management and Prevention, had shared their very own evaluation of the samples in 2022. In that preprint research posted final 12 months, they concluded that “no animal host of SARS-CoV2 may be deduced.”
The analysis checked out 923 environmental samples taken from inside the seafood market and 457 samples taken from animals, and located 63 environmental samples that had been optimistic for the virus that causes Covid-19. Most had been taken from the western finish of the market. Not one of the animal samples, which had been taken from refrigerated and frozen merchandise on the market, and from dwell, stray animals roaming the market, had been optimistic, the Chinese language authors wrote in 2022.
Once they seemed on the completely different species of DNA represented within the environmental samples, the Chinese language authors solely noticed a hyperlink to people, however not different animals.
When a world group of researchers lately took at contemporary have a look at the genetic materials within the samples – which had been swabbed in and across the stalls of the market – utilizing a sophisticated genetic approach known as metagenomics, scientists mentioned they had been shocked to discover a vital quantity of DNA belonging to raccoon canines, a small animal associated to foxes. Raccoon canines may be contaminated with the virus that causes Covid-19 and have been excessive on the listing of suspected animal hosts for the virus.
“What they discovered is molecular proof that animals had been bought at that market. That was suspected, however they discovered molecular proof of that. And in addition that a few of the animals that had been there have been inclined to SARS-CoV2 an infection, and a few of these animals embody raccoon canines,” mentioned Maria Van Kerkhove, WHO’s technical lead for Covid-19, in Friday’s briefing.
“This doesn’t change our strategy to finding out the origins of Covid-19. It simply tells us that extra knowledge exists, and that knowledge must be shared in full,” she mentioned.
Van Kerkhove mentioned that till the worldwide scientific group is ready to overview extra proof, “all hypotheses stay on the desk.”
Some specialists discovered the brand new proof persuasive, if not utterly convincing, of an origin out there.
“The information does level even additional to a market origin,” Andersen, the Scripps Analysis evolutionary biologist who attended the WHO assembly and is likely one of the scientists analyzing the brand new knowledge, instructed the journal Science.
The assertions revamped the brand new knowledge shortly sparked debate within the scientific group.
Francois Balloux, director of the Genetics Institute at College School London, mentioned the truth that the brand new evaluation had not but been publicly posted for scientists to scrutinize, however had come to gentle in information experiences, warranted warning.
“Such articles actually don’t assist as they solely polarise the controversy additional,” Balloux posted in a thread on Twitter. “These satisfied by a zoonotic origin will learn it as closing proof for his or her conviction, and people satisfied it was a lab leak will interpret the weak spot of the proof as makes an attempt of a cover-up.”
Different specialists, who weren’t concerned within the evaluation, mentioned the info could possibly be key to displaying the virus had a pure origin.
Felicia Goodrum is an immunobiologist on the College of Arizona, who lately revealed a overview of all out there knowledge for the assorted theories behind the pandemic’s origin.
Goodrum says the strongest proof for a pure spillover can be to isolate the virus that causes Covid-19 from an animal that was current out there in 2019.
“Clearly, that’s inconceivable, as we can not return in time any greater than we have now by way of sequencing, and no animals had been current on the time sequences could possibly be collected. To me, that is the subsequent neatest thing,” Goodrum mentioned in an e mail to CNN.
Within the WHO briefing, Van Kerkhove mentioned that the Chinese language CDC researchers had uploaded the sequences to GISAID as they had been updating their authentic analysis. She mentioned their first paper is within the strategy of being up to date and resubmitted for publication.
“We now have been instructed by GISAID that the info from China’s CDC is being up to date and expanded,” she mentioned.
Van Kerkhove mentioned on Friday that what WHO would really like to have the ability to do is to seek out the supply of the place the animals got here from. Had been they wild? Had been they farmed?
She mentioned in the middle of its investigation into the pandemic’s origins, WHO had repeatedly requested China for research to hint the animals again to their supply farms. She mentioned WHO had additionally requested for blood exams on individuals who labored out there, in addition to exams on animals which will have come from the farms.
“Share the info,” Dr. Mike Ryan, government director of WHO’s well being emergencies program, mentioned Friday, addressing scientists around the globe who may need related info. “Let science do the work, and we are going to get the solutions.”