More than a year after the initial documented cases in Wuhan, the source of SARS-CoV-2 has yet to be identified, and the search for a direct or intermediate host in nature has been so far unsuccessful.
The low binding affinity of SARS-CoV-2 to bat ACE2 studied to date does not support Chiroptera as a direct zoonotic agent. Furthermore, the reliance on pangolin coronavirus receptor binding domain (RBD) similarity to SARS-CoV-2 as evidence for natural zoonotic spillover is flawed, as pangolins are unlikely to play a role in SARS-CoV-2′s origin and recombination is not supported by recent analysis.
At the same time, genomic analyses pointed out that SARS-CoV-2 exhibits multiple peculiar characteristics not found in other Sarbecoviruses.
A novel multibasic furin cleavage site (FCS) confers numerous pathogenetically advantageous capabilities, the existence of which is difficult to explain though natural evolution...
source: https://link.springer.com/article/10.1007/s10311-021-01211-0
I looked into these lab origin theories for the furin cleavage site last year. The problem with it being a laboratory insertion was that although performing an insertion is relatively easy once you know what to insert, generally it’s beyond current science to independently create mutations for a specific purpose.
It’s a bit beyond me as a non-biologist but my feeling based on the literature was that the lab origin was unlikely. However it is pushed in certain circles partly for ideological reasons, based on evidence that is plausible at first glance but with a lot more digging not entirely convincing evidence.
However, there didn’t really seem to be much neutral expert analysis of the evidence.
At the same time, China risks looking guilty because they are defensive and try to control the information. All this leaves this kind of article with a seemingly plausible scientific and ideological basis that is difficult for laymen and even scientific journalists to evaluate due to the complexity of the science involved, and not many scientists interested in spelling out why the reasoning might be flawed.
You also see in the quote from the article:
“Yes, but your wording makes this sound unlikely — viruses are specialists at unusual events,” is the riposte of David L. Robertson, a virologist at the University of Glasgow who regards lab escape as a conspiracy theory.
The transition from arresting doctors to locking down cities doesn’t make much sense otherwise. You could argue they had motivation to arrest doctors talking about a natural infection if they thought they were spreading fear and disrupting lunar new year festivities, but going to locking down whole cities is about as fear inducing and disruptive as it gets. If that were the motivations for arrest, I’d expect more reluctant and less heavy handed mitigation efforts.
If this were a natural disease and the motivations were to control it as quickly as possible, I’d expect early doctors to be painted as national heroes/propagandized positively very early, similarly to the portrayal of the people that built extra hospital spaces early on.
It’s possible there were different officials involved that changed motivations halfway through, but the lab leak hypothesis offers a more consistent explanation. It makes sense that they would have tried to control the virus quietly if it were a lab leak/wanted to keep it secret, and that they would engage in drastic measures to control it when that didn’t work.
Later discovering they really did have a problem and it was even worse than SARS going to a full lockdown at the main crossroads city right before Chinese New Year (the largest human migration event).
The motivation feels very normal/predicable for China. And also similar to their SARS response. So is SARS also an intentional self inflicted lab leak? And is MERS a secret belt and road initiative?
Seems weird there is a conspiracy about the third deadly coronavirus but not the first two... or the common cold for that matter? Where did that come from and was that a lab leak?
Whole thing smells of lazy arm chair enquiry with a touch of xenophobia
The main difference from SARS is we know there is a virology lab in Wuhan researching coronaviruses right across from the wet market considered the epicenter.
I don’t know enough about the reaction to SARS to know how similar it was, but my understanding was they were similarly draconian internally, and were trying to keep it relatively quiet, but I am not aware of any arrests of doctors early on in SARS outbreaks.
The plausibility of Covid escaping from a lab does not make all viruses plausibly escaped from labs. The reason it’s more plausible for covid are the initial reactions and the proximity of the epicenter to a virology lab studying covid.
I fail to see how it’s xenophobic to consider the lab leak plausible. If anything a natural spread relies on the assumption that the wet market was engaged in unhygienic practices and that someone foreign may have eaten an infected bat.