My basic issue with the lab escape theory: if SARS-CoV2 is a natural strain (and there is at this point no evidence that it isn't), then why assume some researcher was patient zero, when millions of other people catch bat coronaviruses each year? The following interview (from [1]) puts it succinctly:

>“If you do the math on this, it’s very straightforward. ... We have hundreds of millions of bats in Southeast Asia and about 10 percent of bats in some colonies have viruses at any one time. So that’s hundreds of thousands of bats every night with viruses,” Daszak says. “We also find tens of thousands of people in the wildlife trade, hunting and killing wildlife in China and Southeast Asia, and millions of people living in rural populations in Southeast Asia near bat caves.”

>Next, he says, consider the data he’s collected on people near bat caves getting exposed to viruses: “We went out and surveyed a population in Yunnan, China — we’d been to bat caves and found viruses that we thought could be high risk. So we sample people nearby, and 3 percent had antibodies to those viruses,” he says. “So between the last two and three years, those people were exposed to bat coronaviruses. If you extrapolate that population across the whole of Southeast Asia, it’s 1 million to 7 million people a year getting infected by bat viruses.”

>Compare that, he says, to what we know about the labs: “If you look at the labs in Southeast Asia that have any coronaviruses in culture, there are probably two or three and they’re in high security. The Wuhan Institute of Virology does have a small number of bat coronaviruses in culture. But they’re not [the new coronavirus], SARS-CoV-2. There are probably half a dozen people that do work in those labs. So let’s compare 1 million to 7 million people a year to half a dozen people; it’s just not logical.”

[1]: https://www.vox.com/2020/4/23/21226484/wuhan-lab-coronavirus...

Thanks for this. It really change the priors, reading those numbers. I will read all the article.

Weighting against the lab theory also, it seems that there is not record of the "animal passage" technique was being used in the Wuhan Institute of Virology. That seems like something necessary.

There are so many thing that I don't understand in all this, that I'm probably not qualified to have a strong opinion yet (or maybe never). For instance, I don't understand why bats are so prone to be source of viruses instead of other mammals.

If https://healthcareinamerica.us/what-makes-bats-the-perfect-h... is accurate:

* variable body temperature (they heat when they fly) * many species roost very closely in large numbers * weird immune system traits (they have very fast metabolisms, so they present an odd environment for pathogens)

First, understand who Daszak is: yes, he's definitely an expert, but he is also not a disinterested observer. He is the PI on grants from the NIH that funded Bat Coronavirus research in Shi Zhengli's lab at the WIV. He's also stated that he's friends with Shi Zhengli.

The sequence of the virus strongly resembles RaTG13-CoV, a bat coronavirus discovered by WIV. The sequence is almost identical, except for the spike protein. The spike protein strongly resembles a Pangolin CoV also discovered by the WIV. Shi Zhengli and another researcher from WIV are authors on a paper from 2015 where they transplanted the spike protein from one Coronavirus onto the remaining parts of SARS-CoV. They've also done "serial passage" experiments, where they infect either cell cultures or live animals, so that a virus becomes more adapted to that host. One of the animals that they used for these experiments were ferrets, for which SARS-CoV-2's spike shows extremely high affinity.

Now, it's possible that two viruses recombined naturally, but then why did the virus first show up in Wuhan? Wuhan is a thousand miles from the bat caves where they found these viruses in Yunnan. As far as we know, they did not exist in Wuhan, except in the WIV's freezer.

I'd like to hear more about the info in your second paragraph. Is there any reading material (articles, papers, etc) you suggest? It sounds quite interesting, and I had not heard about the spike affinity wrt ferrets.

How many of those 1 to 7 million people live near the lab? The reason the lab escape theory has gained so much traction is that the lab is a few blocks from the reported ground zero for this outbreak.

Of course that doesn't mean that the infection of patient zero happened inside the lab. If I remember correctly, then the researcher, that some have theorized to be patient zero, had recently returned from a field study. So, it's just as likely that they were infected in the field and brought it back with them. The important part is that the infection then spread from the lab and not from the wet market.

>[...] the lab is a few blocks from the reported ground zero for this outbreak.

The Wuhan Institute for Virology (BSL-4 lab) is actually 13 km away. People mixed it up with the unrelated Wuhan Center for Disease Control (BSL-2 lab).

Thank you. I wasn't aware of that.

Does that change anything, if workers from the lab frequent that market, because it's a popular central location to go to shop, eat, meet, whatever, while sloppy safety practices led to at least one of them being infected, and sneeze or cough while wandering around?

Same source, so same potential agenda. If some other new outlet, preferably multiple, are confirming the facts, that would be different. All I heard about the Wuhan lab story was CT stuff back in January and February, until it popped up again recently after Trump, allegedly, pushed US intel to dig into it. And now this, at it's core, anti Fauci piece.

I understand that.

My reasoning has been: new viruses jump from other animals all the time, it has happened in the past, we don't have any reason to think that is not the case this time. It's not surprising at all that it appear in the most populated country in the world.

But after learning about that lab, I have to think: that a new corona-virus appears in the wild a few kilometers out of one of the few labs specialized in corona-virus have to be explained.

Personally, I can't just disregard that because it's not politically convenient.

Numbers favour other sources than labs, as a comment pointed out above. Just apllying logic, it is more likely that the virus jumped from bats to humans in the "wild".

Political convenience aside, the question whther the SARS-Cov-2 escaped from a lab or not doesn't seem to be that important in finding a solution / cure / vaccine. All it does is playing the blame game and distract from the real problems.

Could be. Could also be "they" know exactly what happened, and are to blame for having others rediscovering the wheel (solution) again, because politics, saving face, whatever...