New Paper Adds Support to Covid-19’s Natural Origins
New research from a group of five respected global scientists has concluded the Covid-19 coronavirus that began in China and is now spreading around the world contains at least two genetic clues that indicate it was probably created in nature — and not in a lab.
The team presented its findings in a paper last week on the Virological online forum, providing further argument to counter conspiracy theorists who believe Covid-19 was created by scientists and was accidentally let out. The virus has now infected nearly 80,000 people in China and more than 2,000 in 31 other countries.
China has repeatedly denied the virus was created in a laboratory, with the deputy director of a high-security virology laboratory in Wuhan trashing claims of a link between her facility and the outbreak earlier this month.
Some internet users have theorized that Covid-19 leaked from the Wuhan Institute of Virology, in the Central China city where the outbreak is believed to have begun. Others have claimed that the virus is a manmade biological weapon, though no one has provided credible evidence to support either claim.
The latest research paper came from an international team of specialists from various fields related to virology: W. Ian Lipkin, Kristian G. Andersen, Andrew Rambaut, Edward C. Holmes and Robert F. Garry. Like much research about the virus, the paper has yet to be peer reviewed. Following their analysis of the genomes of different coronaviruses, the group pointed out the new virus has at least two special features that appear to show it wasn’t made in a laboratory or deliberately engineered.
The first is the way the new coronavirus’s “spike proteins” bind with the human receptor protein “angiotensin converting enzyme 2” or ACE2 — which has been shown to be the entry point for some coronaviruses to infect human cells. SARS also has this ability, and the new coronavirus’s does so much more efficiently than SARS. But the mechanism isn’t the optimal one predicted in previous research, suggesting it is the result of mutation and evolution rather than being engineered.
“Thus the SARS-CoV-2 spike appears to be the result of selection on human or human-like ACE2 permitting another optimal binding solution to arise. This is strong evidence that SARS-CoV-2 is not the product of genetic engineering,” the researchers wrote.
The second piece of evidence was the existence of what is known as a “predicted polybasic cleavage site” in the spike protein, a unique feature that the researchers said had not been observed in previous betacoronaviruses, a subcategory that includes SARS and MERS.
Such structures are typically created with participation from the immune system that doesn’t exist outside of animals’ bodies. That appears to show that the formation process of the virus must have occurred naturally or through human-directed passage through generations of animals.
Furthermore, engineering such a virus would likely have left genetic evidence in the form of a “previously used virus backbone,” the researchers wrote. That was not the case with the SARS-CoV-2.
Based on these genetic clues, there are two likely ways the new virus was produced, the team said. One is through a natural selection process in animals before it was passed to humans, and the other was through a natural selection process after the first humans were infected.
They said finding the latent host as well as the earliest infection from the seafood market where the outbreak may have begun would yield more valuable information about the virus’s source. However, experts say most of evidence involving the latter has been destroyed. The group also pointed out that the question of whether the virus came from the older SARS virus is a good topic for future exploration.
Flynn Murphy contributed to this report.
Contact reporter Yang Ge (email@example.com)
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