There's been a lot of talk about the possibility that SAR-CoV-2 originated in the Wuhan Institute of Virology and accidentally escaped, causing the COVID-19 pandemic. There's no evidence that directly supports this possibility and plenty of evidence that casts serious doubt on the Lab Leak Hypothesis. In order to discount the evidence against the hypothesis its supporters claim that scientists are lying and covering up the accidental release with the active cooperation of the Chinese government. Thus, an original scientific hypothesis has morphed into a full-blown conspiracy theory.
As with any conspiracy theory, there are all kinds of "facts" that have only been uncovered on twitter or Reddit but there are also speculations published by the Trump administration. It's very difficult verify or refute many of these "facts."
However, there's one fact that is widely misinterpreted and that's the report of the WHO scientists who visited the Wuhan Institute of Virology in order to investigate the lab leak hypothesis. They concluded that it was "extremely unlikely" so, as you might expect, the WHO scientists are now part of the conspiracy. Here's a copy of the section on the lab leak hypothesis from the WHO full report issued on March 30 2021 [WHO-convened global study of origins of SARS-CoV-2: China Part].
Introduction through a laboratory incidentExplanation of hypothesis
SARS-CoV-2 is introduced through a Laboratory incident, reflecting an accidental infection of staff from laboratory activities involving the relevant viruses. We did not consider the hypothesis of deliberate release or deliberate bioengineering of SARS-CoV-2 for release, the latter has been ruled out by other scientists following analyses of the genome (3).
Arguments in favour
Although rare, laboratory accidents do happen, and different laboratories around the world are working with bat CoVs. When working in particular with virus cultures, but also with animal inoculations or clinical samples, humans could become infected in laboratories with limited biosafety, poor laboratory management practice, or following negligence. The closest known CoV RaTG13 strain (96.2%) to SARS-CoV-2 detected in bat anal swabs have been sequenced at the Wuhan Institute of Virology. The Wuhan CDC laboratory moved on 2nd December 2019 to a new location near the Huanan market. Such moves can be disruptive for the operations of any laboratory.
Arguments against
The closest relatives of SARS-CoV-2 from bats and pangolin are evolutionarily distant from SARS-CoV-2. There has been speculation regarding the presence of human ACE2 receptor binding and a furin-cleavage site in SARS-CoV-2, but both have been found in animal viruses as well, and elements of the furin-cleavage site are present in RmYN02 and the new Thailand bat SARSr-CoV. There is no record of viruses closely related to SARS-CoV-2 in any laboratory before December 2019, or genomes that in combination could provide a SARS-CoV-2 genome. Regarding accidental culture, prior to December 2019, there is no evidence of circulation of SARS-CoV-2 among people globally and the surveillance programme in place was limited regarding the number of samples processed and thereforethe risk of accidental culturing SARS-CoV-2 in the laboratory is extremely low. The three laboratories in Wuhan working with either CoVs diagnostics and/or CoVs isolation and vaccine development all had high quality biosafety level (BSL3 or 4) facilities that were well-managed, with a staff health monitoring programme with no reporting of COVID-19 compatible respiratory illness during the weeks/months prior to December 2019, and no serological evidence of infection in workers through SARS-CoV-2-specific serology-screening. The Wuhan CDC lab which moved on 2nd December 2019 reported no disruptions or incidents caused by the move. They also reported no storage nor laboratory activities on CoVs or other bat viruses preceding the outbreak.
Assessment of likelihood
In view of the above, a laboratory origin of the pandemic was considered to be extremely unlikely.
Please refer to the original report whenever you see the conspiracy theorists making claims about what WHO did or did not report. Those claims are not always accurate; for example, it is widely reported that WHO confirmed that there were COVID-19 case among lab workers in the autumn of 2019 but, as you can see, WHO refuted that part of the conspiracy theory.
