[PeCaN]

I don't think "coronavirus escapes from a lab, in the exact area where the outbreak started, that was studying coronaviruses" is exactly an 'extraordinary claim'. If anything it's the elephant in the room. Are we just supposed to casually ignore that or what….

I think the problem is that when people think of "lab" they think of some sort of devious genetic engineering bioweapons program, and not something considerably more likely but much more mundane like some scientists studying what sort of potentially bad viruses the local bats have.

[jotakami]

Yeah that’s what I’ve been trying to explain to all my reasonable friends who think that the moment I say “it came from a lab” that means this is a bioweapon that was intentionally released. No, actually, there is a chain of evidence that makes an accidental lab leak more plausible than the theory that the virus jumped straight from an animal in a wet market hundreds of miles away from its normal habitat that just happens to be in the same city as a lab that holds samples of virus from that strain.

[root_axis]

How does an "accidental lab leak" happen without a bunch of people at the lab getting infected? Seems like we'd have some evidence if it was an accidental leak.

[javagram]

1. Evidence could be suppressed

2. The person who accidentally leaked it from the lab may not even know it. Research into COVID-19 has estimated up to 20% of people infected may be asymptomatic carriers of the disease who can still spread it to others. Person who works in the lab gets infected, doesn’t get visibly sick, accidentally spreads it to someone in the vicinity of their lab by breathing or coughing or singing or sneezing, virus is now out and they don’t even realize it.

The 1977 H1N1 pandemic is widely believed by scientists to have been an accidental lab release. Evidence as to which lab it escaped from has never been found and we will probably never know. https://mbio.asm.org/content/6/4/e01013-15 “A biosafety lapse in a research laboratory is now most often cited as the cause of the 1977-1978 reemergence of the H1N1 influenza virus strain”

[throwanem]

Please cite your evidence.

[jotakami]

If you’re curious you can find it yourself. Half a dozen comments on this thread have links you can check out. This is an anonymous comment thread, not a tribunal. Do your own homework and make up your own mind.

[legolas2412]

Umm, they were also combining viruses to create "chimeras". Now, this combinational process could be genetic engineering (which has been ruled out I think) or just combining in a petri dish, which I find compelling.

[throwanem]

To create pseudoviruses which are able to infect under lab conditions, but not able to replicate, or to survive in a human or any other organism.

If this were one of those, as has been claimed on the basis of the frequently mis-cited October 2019 WIV paper, anyone in the world would be able to see that by comparing the SARS-CoV-2 sequence accessioned in NCBI's database with one of the many HIV sequences also available there. I've done the alignment myself, against several HIV sequences. So can you; you don't even need a local toolchain, you can pick them and BLAST them right on NCBI's site.

When you do, you'll find the same thing I did: there is no significant similarity between any HIV strain and SARS-CoV-2. So the "escaped chimera" theory is not only implausible on its face given the nature of pseudoviruses, but disproven by genomic evidence, besides.

Please don't spread disinformation.

[legolas2412]

Thanks for the info. I'm clearly not an expert. But I do still have questions.

1) where did hiv sequences come from? Are they the human immuno deficiency virus sequences?

2) you are suggesting that chimeras are created impotent, and that hybrid viruses cannot be created to be effective otherwise. My question is that whatever combination of pangolin and bat viruses is said to have happened naturally in a host, could it happen in a petri dish too? Could WIV be conducting such research? Or are such petri dish chimeras always unable to jump from human to human. Is it a natural property or choice when creating chimeras?

3) it seems that the virus is like SARS but has receptor proteins similar to a known pangolin coronavirus. Is it also possible for two viruses to leak to a single lab employee, and then combine in the first human host right away. It still can be said to leak from the lab in this scenario.

Thanks for having patience for my uninformed opinions.

I'm sure I'm missing

[throwanem]

These are great questions, and thank you for asking them!

1. Yes. The claim based on the misreading of the 2019 paper is that SARS-CoV-2 is actually a lab-created combination of another coronavirus and the human immunodeficiency virus, or HIV. If that were true, the genome of SARS-CoV-2 would incorporate large parts of the HIV genome verbatim. It does not; comparing these genomes for identical or nearly identical subsequences via BLAST, by far the tool most widely used for this purpose, shows no such similarity.

2. Viral recombination occurs when multiple related strains of a given virus infect the same cell at the same time. That can be done in vitro, but I haven't seen any papers from WIV describing such experiments. Notably, the frequently cited 2019 paper describes a totally different kind of experiment, which could not under any circumstances have produced a virus with the genome which SARS-CoV-2 has been observed to have.

3. For that to happen would require two different strains of the same virus to independently develop the same mutation allowing them to cross over and infect humans, and to simultaneously infect the same worker in the lab, and to then recombine in such a way as to produce SARS-CoV-2.

That is not impossible, but it is about as likely to occur as it is for every atom in your body to simultaneously transmute into gold.

[legolas2412]

Thanks for your answer. I'll like to point out that 3 is slightly eased off if the two viruses are already able to jump to humans. In this case, it could be the SARS coronavirus and the pangolin virus whose receptor proteins are similar to ncov19. Then all that is required is for the two viruses to jump over and then recombine. Definitely a possibility.

I find the wet market theory full of such improbabilities too. How is ncov19 relatively close to two known viruses, 1) the sars like bat virus it was 96% similar to, and 2) the pangolin virus with which it has resembling receptor proteins. Seems a lot of coincidence for these two to combine, both of which can jump to humans, and 300 meters from a leading Coronavirus research lab.

I know I'm just repeating the conspiracy theory, but just explaining my position. The virus was found initially at the wet market, and there is no proof of its origin being there. Plus it seems perfectly feasible for it come out of the lab and not be a deliberately engineered virus, atleast not one using the 2019 paper's chimera virus techniques.

[throwanem]

Compared to other families of viruses, coronaviruses recombine unusually often and are unusually likely to produce viable new strains that way. Those traits make them unusually capable of producing zoonoses, which is one of the reasons why they're a subject of particular interest among infectious disease researchers.

Those same traits also produce a high degree of similarity between a lot of genomically differentiable strains of coronavirus, especially since spike proteins tend to be strongly conserved for their direct effect on virulence - a significant mutation there is likely to be maladaptive, if it changes the protein structure enough for cells to no longer uptake a virion that expresses it. So it's not really a surprise to see that two different strains have similar spike proteins, and doesn't really give much basis for inference about relatedness between them.

Another important point is that coronaviruses are so common specifically in bats, which are both extremely plentiful and unusually accommodating hosts for many kinds of viruses including coronaviruses, very often with multiple strains infecting a single host at once. That gives coronaviruses - which, remember, are already good at recombining to produce new strains, every one being possibly able to jump species - more chances at that kind of recombination than they would have otherwise.

Too, bats shed virus in feces the same way humans do, and bat guano is so effective a fertilizer that wars have started over access to supplies of it. So it's not difficult or unlikely to postulate a chain of events like this:

- a recombination event in a bat produces a virus capable of infecting humans,

- which is then deposited in feces used to fertilize a human food crop,

- which is then harvested and taken to a city market to be sold,

- and all it takes for someone to get sick from there is not washing their hands often enough while they're cooking.

To be clear, I'm not saying this is what happened. Nobody knows that yet. But precisely because nobody knows that yet, it's important to consider the relative likelihoods of various ways that the pathogen might have developed into a form that can infect humans, and then reached the point of actually doing so.

That's what I'm doing here. Each stage of this postulated chain of events relies only on things that are already known to frequently occur, and have been so known since long before SARS-CoV-2 was even known to exist.

The result is unprovable, of course, just as with every other theory of this disease's origin that anyone has advanced so far. But it doesn't rely on any unusually small probabilities, and so it seems a lot likelier to me than the combination of a lab accident of a kind known to have happened only a few times in the last two decades, and a simultaneous superinfection of a single researcher with two different strains of coronavirus.