[tripletao]

You were mistaken to say just "coronaviruses" instead of "the greatest diversity of sarbecoviruses", but your comment was otherwise in line with the pre-pandemic consensus--no one expected spillover in Wuhan. Dr. Zhengli Shi, whose research is at the heart of this controversy, wrote in an interview:

> We have done bat virus surveillance in Hubei Province for many years, but have not found that bats in Wuhan or even the wider Hubei Province carry any coronaviruses that are closely related to SARS-CoV-2. I don't think the spillover from bats to humans occurred in Wuhan or in Hubei Province.

https://web.archive.org/web/20201206204844/https://www.scien...

That said, it's no surprise that SARS-CoV-2 first emerged in a city, since it spreads most effectively in dense crowds. Even if spillover occurred in a small village, it's unlikely that enough people would die for anyone to notice until the virus reached a dense city--the virus's IFR isn't that high, and people die of other respiratory diseases every day. There's just no specific reason to expect that city would be Wuhan.

SARS-1 also emerged in a city far from the bat caves; but in that case, infected animals sold in markets there were identified, and the supply chain for those animals led back to likely bat spillover regions. For SARS-CoV-2, no such evidence has yet been found, despite much greater effort to search. That's not proof of unnatural origin, and there are other viruses for which the proximal host isn't known (e.g. Ebola); but that's different from both SARS-1 and MERS.

[fortuna86]

> We have done bat virus surveillance in Hubei Province for many years, but have not found that bats in Wuhan or even the wider Hubei Province carry any coronaviruses that are closely related to SARS-CoV-2.

Doesn't that mean COVID19 occurring naturally in Hubei is highly unlikely ?

[tripletao]

No one expected spillover of a SARS-like virus from bats anywhere in Hubei. That doesn't mean it didn't happen, since the scientific consensus is sometimes wrong; but no significant new evidence has yet emerged to make that more likely. The closest bat viruses in nature (BANAL-20) were discovered post-pandemic in Laos.

Most people who believe SARS-CoV-2 arose by natural zoonosis propose something similar to SARS-1's wildlife trafficking conduit. It's also possible that a human was infected elsewhere, and then traveled to Wuhan and seeded the pandemic--the spread of SARS-CoV-2 is highly stochastic until the case count gets big, so they wouldn't necessarily have seeded other clusters along the way. It's all pretty mysterious though, much more so than the emergence of the two previous coronavirus human pathogens (SARS-1 and MERS).

[fortuna86]

What do you make of reporting that claims a virus almost identical to COVID19 was previously identified and studied at the Wuhan lab as early as 2012?

https://www.reuters.com/business/healthcare-pharmaceuticals/...

> Since the middle of last year, Li's postgraduate thesis has been circulated online as purported evidence that a coronavirus very similar to SARS-CoV-2 could have been infecting humans as early as 2012.

> Some also believe the paper provides circumstantial evidence for broader allegations that WIV had captured, studied and conducted "gain of function" experiments on viruses found in the mine, including RaTG13.

> First identified in 2016, RaTG13 shares 96.2% of its genome with SARS-CoV-2, according to a paper released by Shi and other researchers early in February 2020, just weeks after the first COVID-19 cases had been identified in Wuhan.

[tripletao]

That's correct but out of date. RaTG13 used to be the closest known bat virus to SARS-CoV-2, but (a) it's far enough that there's no simple path to derive SARS-CoV-2 from it in the lab, and (b) it's not anymore, with the discovery of BANAL-20. The WIV was also sampling in Laos near where BANAL-20 were found, but hasn't published any closer genomes.

For the conspiracy-minded, I'd note that the WIV had published a subset of RaTG13's genome pre-pandemic, enough for others to identify the similarity. So they pretty much had to publish the rest of the genome post-pandemic, since it was obvious they had something interesting. The WIV used to have a public database of viral genomes, but it went offline around Sep 2019. They cite "hacking attempts" as the reason, but still haven't reinstated it in any form.

I'd personally guess that the Chinese government doesn't know whether SARS-CoV-2 arose naturally or unnaturally, and doesn't want to know--their preferred story (imported into China on frozen food) is near-certainly false, so no truth can benefit them. It's very hard to say though, all pretty mysterious. There are significant unexplored paths for investigation within reach of American subpoena though, e.g. in any cloud services used by the WIV for genomic data.