Where are all the bats infected with this virus? It it came from a bat, it would have had to be circulating in the bat population a LOT to mutate enough to jump to humans, right?
So...why not go find a bad, identify the parent virus, and close this whole thing out?
[1]https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndr...
Guess who found the bat host? Shi Zhengli of the very WIV in question.
I did plenty of these gain-of-function experiments in my postgrad studies. Mice tumours cells given genes to super-express certain cell adhesion molecules. Without this kind of approach, it is difficult to impossible to study these reactions. You just gotta be careful.
> In late May 2003, studies were conducted using samples of wild animals sold as food in the local market in Guangdong, China. The results found that the SARS coronavirus could be isolated from masked palm civets (Paguma sp.)
and
> The SARS epidemic began in the Guangdong province of China in November 2002 ... Chinese government officials did not inform the World Health Organization of the outbreak until February 2003.
That's six months from the start of the outbreak, and less than four months from WHO being informed, not three years.
Where did you get your "three years" figure from?
So a very likely explanation is some low level employees grabbed some bats, got their suits and vehicles contaminated didn't clean things properly, drove down to the Wuhan laboratory, and rested in town spreading virus contaminated dust or if they were already sick, their virus filled respiration about.
No lab leak needed, just the regular practices when "Wuhan Institute of Virology in China sampled thousands of horseshoe bats in locations across the country", and those doing so were being sloppy, as they have been known to be repeatably.
[0] Bat cave solves mystery of deadly SARS virus — and suggests new outbreak could occur - December 2017 https://www.nature.com/articles/d41586-017-07766-9
"In late 2006, scientists from the Chinese Centre for Disease Control and Prevention of Hong Kong University and the Guangzhou Centre for Disease Control and Prevention established a genetic link between the SARS coronavirus appearing in civets and humans, bearing out claims that the disease had jumped across species.[62]"
It goes on to state that the bat link was confirmed in 2017.
Also, my understanding (quite possibly wrong) is that while humans can get sick from bats, as cave workers did in Southern China, those viruses aren't contagious in the sense that the sick humans go on to infect others. "Since no case of an epidemic caused by direct bat-to-human transmission has yet been demonstrated, it is thought that the transfer to humans more probably took place via an intermediate host species in which the virus could evolve and move towards forms likely to infect human cells." [1] If that's right then your explanation of spilled bat samples is incomplete: it doesn't explain what caused the bat samples to adapt into a form that could spread among humans. That sort of puts us back at square 1. Another way of saying this is that if your explanation is likely, then we'd have expected the pandemic to have started where the bats are - through sick cave workers or something similar. But in fact it started far away.
[1] https://news.cnrs.fr/articles/the-origin-of-sars-cov-2-is-be...
The leader of the Wuhan team went there with a team to collect samples and animals. In the early days of Covid, those samples were re-examined and it turned out that the genome of the Covid strain was very similar to the Covid 19 virus. So the conclusion was taken that those bats must have been the origin where Corona somehow started. Somehow nobody at that time thought much about the fact that those samples were kept in Wuhan, exactly where the outbreak started.
Bats have a very unusual immune system in that they can harbor viruses without the virus killing the bat or the bat killing the virus.
It's one of the things that makes them ferociously good incubators for a cross-species mammalian plague. The other things are that they fly (so can cover larger distances than most mammals) and have communal living (so can transmit to each other very readily).
Hence I didn't say we evolved from chimpanzees, even though it'd've suited the snow clone better