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From the journal Nature - 08 June 2021 - Arguments that the coronavirus (SARS-CoV-2) escaped from a lab in Wuhan, China (It's crucially important to find out the origins of the pandemic in order to prevent it from happening again)
https://www.nature.com/articles/d41586-021-01529-3
The WHO has yet to reveal the next phase of its investigation. But China has asked that the probe examine other countries. Such reticence, and the fact that China has withheld information in the past, has fuelled suspicions of a ‘lab leak’. For instance, Chinese government officials suppressed crucial public-health data at the start of the COVID-19 pandemic.
Scientists don’t have enough evidence about the origins of SARS-CoV-2 to rule out the lab-leak hypothesis, or to prove the alternative — that the virus has a natural origin.
In theory, COVID-19 could have come from a lab in a few ways. Researchers might have collected SARS-CoV-2 from an animal and maintained it in their lab to study, or they might have created it by engineering coronavirus genomes. In these scenarios, a person in the lab might have then been accidentally or deliberately infected by the virus, and then spread it to others — sparking the pandemic.
One holds that it’s suspicious that, almost a year and a half into the pandemic, SARS-CoV-2’s closest relative still hasn’t been found in an animal. Another suggests it is no coincidence that COVID-19 was first detected in Wuhan, where a top lab studying coronaviruses, the WIV, is located.
Some lab-leak proponents contend that the virus contains unusual features and genetic sequences signaling that it was engineered by humans. And some say that SARS-CoV-2 spreads among people so readily that it must have been created with that intention. Another argument suggests that SARS-CoV-2 might have derived from coronaviruses found in an unused mine where WIV researchers collected samples from bats between 2012 and 2015.
As for finding an intermediate host animal, researchers in China have tested more than 80,000 wild and domesticated animals; none have been positive for SARS-CoV-2. But this number is a tiny fraction of the animals in the country.
Another feature of SARS-CoV-2 that has drawn attention is a combination of nucleotides that underlie a segment of the furin cleavage site: CGG (these encode the amino acid arginine). A Medium article that speculates on a lab origin for SARS-CoV-2 quotes David Baltimore, a Nobel laureate and professor emeritus at the California Institute of Technology in Pasadena, as saying that viruses don’t usually have that particular code for arginine, but humans often do — a “smoking gun”, hinting that researchers might have tampered with SARS-CoV-2’s genome.
China has not conceded to demands for a full lab investigation.
“We want an answer,” says Jason Kindrachuk, a virologist at the University of Manitoba in Winnipeg, Canada. “But we may have to keep piecing bits of evidence together as weeks and months and years move forward.”
Nature 594, 313-315 (2021)
doi: https://doi.org/10.1038/d41586-021-01529-3
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