This article draws on the emails and other information to provide a good summation and timeline of these developments. The emails from the scientists followed a conference call on 1 February 2020, and indicated their view that the virus structure was strongly indicative of non-natural origin, with one saying he "has a hard time to explain that outside the lab", while another said he "can't think of a plausible natural scenario... can't figure out how this gets accomplished in nature".
Yet within 48 hours this same group of scientists publicly repudiated this view, and followed up with an influential paper that effectively shut the debate down until early 2021, with the lab-leak theory dismissed as a "conspiracy theory" and censored on social media.
How to account for this switch? The emails, only released because of Congressional pressure, reveal some disturbing possibilities as to motive.
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Now we know what those leading scientists really thought. Emails exchanged between them after a conference call on 1 February 2020, and only now forced into the public domain by Republicans in the US Congress, show that they not only thought the virus might have leaked from a lab, but they also went much further in private. They thought the genome sequence of the new virus showed a strong likelihood of having been deliberately manipulated or accidentally mutated in the lab. Yet later they drafted an article for a scientific journal arguing that the suggestion not just of a manipulated virus, but even of an accidental spill, could be confidently dismissed and was a crackpot conspiracy theory.
Now, however, we have an email from Farrar, sent on Sunday 2 February to Francis Collins, head of the National Institutes of Health, and Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases. It recounts the overnight thoughts of two other virologists Farrar had consulted, Robert Garry of Tulane University and Michael Farzan of the Scripps Research Institute, as well as Farrar’s own thoughts. Even after the call, their concern centred on a feature of the SARS-CoV-2 genome that had never been seen in any other SARS-like coronavirus before: the insertion (compared with the closest related virus in bats) of a 12-letter genetic sequence that creates a thing called a furin cleavage site, which makes the virus much more infectious.
Farzan, said Farrar, ‘has a hard time to explain that outside the lab’ and Garry ‘can’t think of a plausible natural scenario… can’t figure out how this gets accomplished in nature’. Farrar himself thought, on that Sunday, that ‘a likely explanation could be something as simple as passage [of] SARS-like CoVs in tissue culture on human cell lines (under BSL-2) for an extended period of time, accidentally creating a virus that would be primed for rapid transmission between humans via gain of furin site (from tissue culture) and adaption to human ACE2 receptor via repeated passage’. Translated: repeatedly growing a virus in human cells in a lab will alter its genome through natural selection so it adapts to human hosts.