A Nobel prize-winning US biologist, who has been widely quoted describing a “smoking gun” to support the thesis that Covid-19 was genetically modified and escaped from a Wuhan lab, has said he overstated the case.
David Baltimore, a distinguished biology professor, had become one of the most prominent figures cited by proponents of the so-called lab leak theory.
Originally quoted in an article in the Bulletin of the Atomic Scientists in May, and widely requoted since, Baltimore had appeared to suggest that a specific feature in Covid-19’s genome, known as the furin cleavage site, was the “smoking gun” to the theory the virus had been contained inside a laboratory and then escaped via a leak.
“These features make a powerful challenge to the idea of a natural origin for Sars2,” he said at the time.
In recent days, however, Baltimore has told a fellow researcher, the scientific journal Nature and the LA Times that – while he had been quoted accurately in the bulletin – he should not have used the phrase “smoking gun” and was uncertain what the feature proved regarding the origins of the virus – natural or otherwise.
In an email exchange with the Los Angeles Times, Baltimore conceded he had overstated the case and that he had an open mind on the matter.
“[I] should have softened the phrase ‘smoking gun’ because I don’t believe that it proves the origin of the furin cleavage site but it does sound that way.
Baltimore also clarified his stance in an exchange with Nature, saying: “There are other possibilities and they need careful consideration, which is all I meant to be saying.”
Photo: A plastic model of coronavirus at the Institute of Tropical Medicine in Antwerp, Belgium,. EPA-EFE/STEPHANIE LECOCQ