Did Covid-19 escape from a Wuhan lab? Here’s what we know

What was once dismissed as a baseless conspiracy theory is now being taken more seriously.

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Is the coronavirus man-made? Until very recently, you’d have had the distinct impression that anyone entertaining the “lab-based origin” theory of the Covid-19 virus either had a screw loose or was advancing a Trumpist, anti-China political agenda. Proponents of the idea were ridiculed in the press, and some had their social media accounts removed for spreading misinformation.

Not so any more. Having argued strongly against the idea early in 2020, President Biden's chief medical adviser, Dr Anthony Fauci, has stated that he’s now “not convinced” that the virus has a natural origin, and that more research is required. Mainstream media sources are now regularly running stories that imply that the virus might not be the result of a natural process of evolution.

Broadly there are four possibilities for the origin of Sars-CoV-2 (as the coronavirus that causes Covid is known). They are:

  1. It’s a deliberately engineered bioweapon, released intentionally by China to devastate the world.
  2. It’s the result of reckless “gain-of-function” research at the Wuhan Institute of Virology, where scientists genetically modified a coronavirus to have new features to learn more about it, but accidentally let it escape.
  3. It evolved naturally, without any genetic modification, but did so because scientists were spending a lot of time around animals like bats, researching their coronaviruses. It then escaped accidentally.
  4. It evolved naturally and began infecting humans without the involvement of any labs or scientists.

Nobody sensible believes number one. The “official story” as of a few months back was number four. Recently, it's appeared as if numbers two and three have suddenly become more plausible. Are they?

The sheer length of time that the “lab leak” versus “natural origin” debate has been running in scientific papers and blog posts, and on social media has left us with a dizzying array of arguments and counter-arguments. Some of the pro-lab leak points are circumstantial: isn’t it a bit too much of a coincidence that Wuhan is the origin of the pandemic and happens to have a huge virology lab that studies coronaviruses? There are also reports of safety failures at that lab – might such a failure have unleashed Sars-CoV-2 on the world?

Maybe. But we’d need to go well beyond speculation like this if we’re to be sure.

[See also: Stuart Ritchie on how sewage testing could help tackle the spread of Covid]

Another common pro-lab leak argument focuses on a molecular feature of the virus: its furin cleavage site. This allows the virus to break apart its spike protein and enter the host’s cells, where it begins reproducing. Other similar Sars coronaviruses don’t have a furin cleavage site, and enter the cell by other means. It seems incredibly unlikely, say the lab leak proponents, that a furin site could have evolved on its own in just this particular virus. Much more likely, they say, that it was put there deliberately, in a lab experiment.

When I first read this argument, I had a shiver of recognition. This is essentially identical reasoning to that used by proponents of “intelligent design” (creationism by another name), who in the early 2000s advanced the claim that the bacterial flagellum, a spinning tail that allows some types of bacteria to move, is so complex it could never have evolved via natural selection, and must therefore have been created by God. The reasoning became known as the “Argument from Personal Incredulity”: I can’t imagine how it evolved, and therefore it didn’t evolve.

In fact, there is a plausible mechanism for the evolution of the flagellum. And the furin binding site has evolved independently multiple times on several types of coronaviruses, making it much less surprising that it evolved in Sars-CoV-2. Although the argument might seem compelling at first (especially if, like me, you’re hardly an expert on viruses), the wider context makes it seem far less impressive.

That this specific argument fails doesn’t mean the lab leak theory is untrue. The origins of Sars-CoV-2 aren’t yet known to any degree of certainty, and until we have a much better theory we shouldn’t discount any solid evidence that’s forthcoming (though I really do mean solid evidence: vague rumours about intelligence reports aren't sufficient).

But we should always have been open to such evidence. Just like the ill-advised campaign against face masks in early 2020, the initial certainty from authority figures – in that case “masks do not work”; in this case “lab leak theorists are cranks” – was never warranted.

It’s tempting to try to crush unorthodox beliefs with sure-sounding statements, like those of the experts early in the pandemic. But the repeated failures of expertise during Covid suggest that it’s better – more scientific, and with less chance for backfire – if authorities hold their beliefs lightly.

At present the evidence suggests to me that Sars-CoV-2 has a purely natural origin, but I’m not sure about that – and today’s unwarranted certainty is tomorrow’s misinformation. As Nietzsche might have said if he’d been around in 2021: whoever fights misinformation should see to it that in the process he does not spread misinformation himself.

[See also: will vaccines protect against all international Covid variants?]

Stuart Ritchie is a psychologist at King’s College London and the author of Science Fictions: How Fraud, Bias, Negligence and Hype Undermine the Search for Truth

This article appears in the 02 June 2021 issue of the New Statesman, Return of the West

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