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In the latest volley of debate about the origins of the coronavirus, this week a group of scientists gave a presentation. review Scientific findings that they claim show a natural spread from animal to human caused a pandemic far more likely than a laboratory event.
Among other things, scientists are at markets in Wuhan, China. sold live animals susceptible to the virusincluding palm civets and raccoon dogs two years before the pandemic began. They observed the striking similarity of the emergence of Covid-19 to other viral diseases emerging through natural spreads, and noted several newly discovered viruses in animals closely related to the one causing the new pandemic.
It happens back and forth among scientists when working with intelligence agencies. end of summer deadline Providing President Biden with an assessment of the origin of the pandemic. now one division As to which scenario is more likely of viral origin among intelligence officials.
new paper, which posted online Written by a team of 21 virologists Wednesday but not yet published in a scientific journal. All four of them collaborated. 2020 paper At Nature Medicine, he largely dismissed the possibility that the virus could become a human pathogen through laboratory manipulation.
In the new paper, the scientists provided further evidence that the virus was transmitted from an animal host outside the laboratory. Virologist and co-author Joel Wertheim of the University of California at San Diego said a key point in support of a natural origin is the “uncanny resemblance” between the Covid and SARS outbreaks. Both viruses emerged. He said the first known cases emerged in China in late autumn near urban animal markets. — Wuhan in case of Covid and Shenzhen in case of SARS.
The new paper points out that in the SARS epidemic, scientists traced the origin of viruses that eventually infected bats far from Shenzhen.
Dr. Based on the distribution of new coronavirus-like viruses in Asia, Wertheim and colleagues predict that SARS-CoV-2 will also originate far from Wuhan.
Since it first surfaced in the last months of 2019, the viral culprit of this pandemic has yet to arise naturally in any animal.
Another team in May 18 scientists published a letter arguing that the possibility of a lab leak should be taken seriously, as there is little evidence to support a natural origin of the coronavirus or a leak from a lab. Wuhan, where the pandemic was first documented, is home to the Wuhan Institute of Virology, or WIV for short, where researchers have been researching coronaviruses from bats for years.
Michael Worobey of the University of Arizona, one of the signers of the May 2021 letter, co-authored the new paper advocating a natural spread.
He said his views improved as more information became available. Dr. Other reasons for Worobey’s change included growing evidence of the Huanan livestock market in Wuhan. When the pandemic first appeared in Wuhan, Chinese authorities tested hundreds of samples from market animals, and none of them found the coronavirus.
But last month, a research team submitted an inventory of 47,381 animals from 38 species sold in Wuhan markets between May 2017 and November 2019. This inventory included species such as civets and raccoon dogs that can serve as intermediate hosts for coronaviruses.
Dr. Worobey called this work “a game-changing article.”
He also drew attention to the timing of the earliest Covid cases in Wuhan. Dr. “The Huanan market is at the very epicenter of the epidemic and subsequent cases are spreading out into space from there,” Worobey said in an email.
“No early cases clustered near WIV, which is the focus of most speculation about a possible lab escape,” he said.
But other scholars say such arguments are speculative, and the new review is mostly a repetition of what was already known.
“It basically boils down to an argument that, since nearly all previous pandemics have been of natural origin, that too must have happened,” said David Relman, a microbiologist at Stanford University who organized the May letter to Science.
He noted that he did not object to the natural origin hypothesis as a plausible explanation for the origin of the pandemic. However, Dr. Relman thinks the new paper offers “a selective sampling of findings to argue a side.”
Dr. Worobey and colleagues also presented evidence against the supposed idea in their new paper. functional gain research This deliberately altering the function of a virus may have played a role in the pandemic. The researchers argue that the coronavirus genome shows no compelling signatures of manipulation. And the diversity of coronavirus scientists discovered in Asian bats may have served as the evolutionary source for Covid-19.
But that’s a casual discussion, said Richard Ebright, a Rutgers University molecular biologist and a persistent critic of attempts to reduce the possibility of lab leaks.
Dr. Ebright said a WIV lab worker may have contracted the coronavirus while on a field trip to study bats or while processing a virus in the lab. He argued that the new paper does not address such possibilities.
Dr. “The review does not advance the discussion,” Ebright said.
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