- If there was any hard evidence actually proving they had SARS-CoV-2 in the lab before the pandemic, it will be long gone. Only an independent full access forensic level investigation would ever find any sign that evidence was destroyed, and that is never going to happen.
- It seems extremely unlikely to me that anyone from within China will A) blow the whistle or B) that we would hear about it.
- If a whistleblower were to escape the country, China would be able to claim they are lying, and it is a plot by the West to oppress the Chinese people etc. The chance that the whistleblower would be carrying irrefutable evidence of a lab leak is again almost zero.
We can keep shaking the tree, but I don't think anything truly satisfying is going to fall out. Consider that even if the USA for example had actual evidence of a lab leak, they would be better off using this as leverage over China secretly than releasing it publicly.
What actually can and should happen, is that some major change comes to virology research to absolutely minimise the chance of another lab origin pandemic. Wherever SARS-CoV-2 came from, we have had lab leaks before and we will have them again, that much is certain.
It’s 96.2% similar not 98%. The issue is that coronaviruses in nature don’t mutate fast enough for that to be the missing link, and they have tested something like 80,000 animals since the outbreak without finding anything closer. One possibility is that the gap was closed through gain-of-function or serial passage research.
> Clues to the transition from bat virus RaTG13 to human virus SARS-CoV-2 may lie within the 4% of the genome sequences that diverge. Evolutionary biologists estimate it would have taken at least 50 years for the bat virus to have mutated itself into SARS-CoV-2, considering known, natural mutation rates of viral genomes.
It goes on to say, that it’s possible this virus is just different.
This paper states 20-50 years an an estimate. [1]
> Bats belong to the usual suspects for zoonosis, and indeed, a bat virus that shared 96% sequence identity with SARS-CoV-2 was isolated in Yunnan /China in 2013. However, a 4% sequence difference (>1000 bp) would indicate 20 to 50 years of separation from SARS-CoV-2, making this bat isolate an unlikely direct source for the nascent epidemic. Chinese researchers explored tissue and faecal samples from 227 bats representing 20 species living in China, collected between May and October 2019 and analysed them by metagenome sequencing. This investigation found that the closest relative of SARS-CoV-2 in this sample set shared 93.3% sequence identity over the entire genome, less than the bat coronavirus isolated in 2013 from the same province, Yunnan (Zhou et al., 2020).
I’m not a virologist, just trying to keep up with this story. It seems like a consensus that 3.8% is a large chasm to cross in that time frame, but there could be things we don’t know or possibly viruses that are closer to SARS-CoV2 that we haven’t sequenced yet. I think the most important thing to note is that there hasn’t been enough evidence to rule out a gain-of-function lab leak hypothesis given what we know today about viruses and there wasn’t a year ago either.
[0] https://dnascience.plos.org/2021/04/15/3-possible-origins-of...
[1] https://sfamjournals.onlinelibrary.wiley.com/doi/10.1111/175...