Viral: The Search for the Origin of COVID-19

But bat coronaviruses generally do not have furin cleavage sites, raising the question of how Sars-Cov-2 had acquired its own. RaTG13, the virus that the Wuhan Institute had admitted working with, was the closest known viral relative of Sars-Cov-2, but by virology standards it was still relatively distant, and it lacked the furin cleavage site.

They also realized that other coronaviruses in the same family as Sars-Cov-2 did not have a similar password, much less one positioned so well. That finding raised the question of why Sars-Cov-2 did. A few scientists speculated openly whether the virus had been designed or modified in a laboratory. But most dismissed those questions as irrelevant,

Genetic sequencing showed that SARS-2 is 96.2 percent identical to a coronavirus found years ago in a bat in a cave in Yunnan, China (that virus is known as RaTG13). This confirms that SARS-2 originated in bats, where it probably circulated unnoticed for decades, but the virus also might have spent some time in pangolins before coming to our own sp

But the theory was discounted within months, because Chinese researchers could not find Sars-Cov-2 in tissue samples of animals taken from the Wuhan wet market.

Essentially, the natural origins theory went something like this: Lots of coronaviruses exist. They regularly mutate and trade pieces of their genomes with each other. An intermediate host will be found sooner or later, even if some of the obvious candidates haven’t panned out.

That cave—like other caves that had large numbers of the bats that were the original animal hosts for naturally occurring coronaviruses—was nowhere near Wuhan. It was located in southern China, several hundred miles away. And the Chinese couldn’t trace a chain of human transmission from that region to Wuhan. They had reported no early cases in the

So Sars-Cov-2 had been the subject of what could only be called a cover-up at the highest levels of the Chinese government, it had unusual genetic elements, and it had emerged in the city that held a lab performing risky research on coronaviruses. As I sometimes liked to write on Twitter, Nothing to see here, folks!