There is biosecurity and biowarfare literature on pretty much every single virus you can imagine - generally it's about how it might be modified to be used as a bioweapon. And really, coronaviruses are quite good platforms for making debilitating airborne weapons.
SARS-CoV itself as a bioweapon is simply not infectious enough, it was sucessfully contained dozens of times. It's also not that lethal to military-age men, for 20-29 year olds CFR is around 1% and for 30-39 year olds it's around 3% (taking data from infections in the PRC and in HK as there is the least low-detection bias). But it definitely has a lot of potential if you engineer it. For reference, the average age of a soldier in WW2 was 26.
SARS-CoV-2 is complete trash as a bioweapon, an entire carrier was infected and no one died. Debilitation was minimal. It's infectious enough, but it's very bad at actually killing military aged people.
But certainly, they could be engineered to be suitable. That's not the claim I was replying to - the claim I was replying to was that in it's natural form it was a bioweapon.
>The rest of your posts seems to gather support for other hypothesis, not as much attacking the lab leak theory as highly unlikely.
Likelihoods are relative. Everyone agrees that likelihood for a lab escape is fairly low - those are relatively rare. The argument is that the normal process for viruses to reach humans - which was the case for literally every single other pandemic ever - is unlikely thus making lab escape more likely relatively.
I did, however, add a few points that go against the likelihood of an undetected lab escape - which is that the existence of the sample would almost certaintly be known.
No known treatment or vaccine. Targets the decision makers (presidents and ministers and military generals are older, and a virus is easier to reach them, than a bullet is). SARS-CoV has super-spreader events, and asymptomatic spread, making it very difficult to contain. It spreads incredibly easily (near-airborne), in confined spaces such as airplanes, but even the toilet plumbing, or shared airco. It offers plausible deniability, by pointing to a natural spill-over event or unsanitary meat markets. It causes enormous economic damage (the economy, not the cannon fodder, being the subject of modern warfare) and cultural damage (tracking and containment is costly and invasive as it damages trust in a free society). It is most readily available to small states and terrorist groups by extracting from live civet cats. Military-aged terrorists spreading SARS-CoV by simply boarding airplanes and visiting hot spots, and not even dying themselves, so they can do it all over again. SARS-CoV in first stages has vague symptoms, similar to other, more common viruses, which would give a pandemic a head start. Pandemics are good PR for fear-based terrorism. The strain on the hospitals is enormous, and military-aged men are too worried to reserve a bed for their elderly parents or their recovery.
More in the vast literature.
> SARS-CoV-2 is complete trash as a bioweapon.
If complete trash, I would not be afraid of Iran being able to press a button and release SARS-CoV-3 for a 2020 repeat. Even if looking at viral bioweapons from the comical anthrax perspective: SARS-CoV-2 killed over 2 million people.
> that the existence of the sample would almost certaintly be known.
Yes. It would make sense that it would be known. And if it would be known, that would probably sufficiently proof the lab leak hypothesis and end this quarrel. We wouldn't need to talk about probabilities much anymore. But that same argument kinda also works against the zoonotic origin hypothesis. It would make a lot of sense that after a year, we found the intermediate host, or patient 0. If there was a clear epidemiological explanation for a zoonotic origin, it would almost certainly be known. Maybe there really isn't.
Not true - there are basically known vaccines to SARS-CoV, they just never got to human efficacy trials because the disease went extinct. But, given their efficacy when repurposed as SARS-CoV-2 vaccines, they were probably quite effective.
As for super-spreading events, this is a double edged sword. It makes it very infectious when nothing is being done to try and stop it, but it means that if there are even cursory measures the chances of the infection stalling are much higher as you're relying on a low number of people actually spreading it.
SARS-CoV may have vague symptoms in the early stages - but it has symptoms. You want a virus that can spread asymptomatically for it to be a major burden, so that makes it less useful.
If your goal is to strain hospitals and create fear, by far the best tools would be humanized avian flu, or a vaccine resistant strain of measles.
>Yes. It would make sense that it would be known. And if it would be known, that would probably sufficiently proof the lab leak hypothesis and end this quarrel. We wouldn't need to talk about probabilities much anymore. But that same argument kinda also works against the zoonotic origin hypothesis. It would make a lot of sense that after a year, we found the intermediate host, or patient 0. If there was a clear epidemiological explanation for a zoonotic origin, it would almost certainly be known. Maybe there really isn't.
I think you're missing the point. If there was a lab escape, the likelihood for the sample to be known is very high. This means that given priors of no known samples, the likelihood for a lab escape is lower.
It's also completely unrealistic to expect to find the host or patient zero after a year for a zoonosis. It took 40 years to find the intermediate host for Ebola, and four years to find it for SARS. For some epidemics, we never found a solid intermediate host. Patient zeros are basically never found, either, unless the disease is incredibly pathogenic and virulent - which SARS-CoV-2 isn't. If you look towards past epidemics that originated from zoonosis with a similar disease profile, you will find that it takes years to decades to conclusively find an intermediate host, and that patient zero is basically never found with any degree of certainty, meaning that the current scenario is perfectly congruent with expectations.