The former New York Times science writer Nicholas Wade is no stranger to controversy. Now he has written a long essay arguing that the “lab leak” hypothesis is more plausible than the “natural origin” theory.
As readers may be aware, there are two main theories for SARS-CoV-2’s origin. One maintains that the virus originated in bats, and then jumped to humans, most likely via an intermediate host species. The other states that the virus originated in a lab, but then accidentally escaped, perhaps due to inadequate safety protocols.
At the start of the pandemic, the lab leak hypothesis was dismissed as a “conspiracy theory” by many scientists and much of the mainstream press. Since then, however, more and more evidence has emerged that casts doubt on the alternative, natural origin theory.
Back in January, New York Magazine ran a long essay by the journalist Nicholas Baker, which tentatively argued the lab leak theory could be right. Then in March, Undark ran a piece by the science writer Charles Schmidt, stressing that the virus’s origin is very much an open question. At the end of March, The Telegraph ran a similar article by the author Matt Ridley and the biologist Alina Chan. (Indeed, the pair are writing a book on the pandemic’s origin called Viral, to be published later this year.)
In his new essay, Wade adopts a more forceful tone. Though he acknowledges “there is no direct evidence for either theory”, he maintains that the lab leak theory provides a far better explanation of the available facts. As Wade notes:
It’s documented that researchers at the Wuhan Institute of Virology were doing gain-of-function experiments designed to make coronaviruses infect human cells and humanized mice. This is exactly the kind of experiment from which a SARS2-like virus could have emerged. The researchers were not vaccinated against the viruses under study, and they were working in the minimal safety conditions of a BSL2 laboratory. So escape of a virus would not be at all surprising. In all of China, the pandemic broke out on the doorstep of the Wuhan institute. The virus was already well adapted to humans, as expected for a virus grown in humanized mice. It possessed an unusual enhancement, a furin cleavage site, which is not possessed by any other known beta-coronavirus, and this site included a double arginine codon also unknown among beta-coronaviruses.
By contrast, there are several pieces of evidence that the natural origin theory has great difficulty explaining:
No one has found the bat population that was the source of SARS2, if indeed it ever infected bats. No intermediate host has presented itself, despite an intensive search by Chinese authorities that included the testing of 80,000 animals. There is no evidence of the virus making multiple independent jumps from its intermediate host to people, as both the SARS1 and MERS viruses did. There is no evidence from hospital surveillance records of the epidemic gathering strength in the population as the virus evolved. There is no explanation of why a natural epidemic should break out in Wuhan and nowhere else. There is no good explanation of how the virus acquired its furin cleavage site, which no other beta-coronavirus possesses, nor why the site is composed of human-preferred codons.
Though some scientists claim we may never pinpoint the exact origin of SARS-CoV-2, the debate will no doubt continue over the coming weeks and months. In the meantime, Wade’s essay is worth reading in full.