U.S. scientists clarify signing Science letter not in favor of lab-leak hypothesis

WASHINGTON, July 29 (Xinhua) -- Two U.S. biology professors have clarified publicly that their signatures on a letter to the Science magazine in May over COVID-19 origin tracing should not be interpreted as support for the lab-leak hypothesis.

In a recent letter to TWiV, or This Week in Virology, a weekly podcast about viruses, Pamela Bjorkman, professor of Biology and Biological Engineering at the California Institute of Technology (Caltech), admitted that she had been too naive to anticipate that the letter would be used to promote the lab-leak scenario, widely considered by scientists as a conspiracy theory.

"I thought the letter would have the effect of prompting more funding for searching for natural viruses in animal reservoirs, which I personally have always assumed represent the origin of SARS-CoV-2 infections in humans," she said. "Perhaps naively, I did not anticipate that the letter would be used to promote the lab origin hypothesis."

On May 14, 18 researchers published a letter in the magazine calling for more investigation to determine the origin of the pandemic, and noting that "theories of accidental release from a lab and zoonotic spillover both remain viable," according to the website of the magazine.

The letter was interpreted by many in the West as giving "a big credibility boost" to the COVID-19 lab-leak hypothesis, and was used as ammunition to up pressure on China in regard to the origin tracing of the deadly virus.

After seeing what's happening around the letter in Science, Bjorkman seemed to try to back away from it.

"Looking back on the wording of the letter, however, I now think that I should have realized this would happen and should have been more proactive -- either not signed the letter at all or else requested more wording changes to make my position clear," said the professor.

In a recent email to Xinhua, Marta Murphy, Bjorkman's administrative assistant, confirmed that Bjorkman signed the Science letter to "advocate for increased funding for researching the origins of SARS-CoV-2."

"Although she believes that SARS-CoV-2 more likely passed into humans from an animal source than from a lab, she is not an expert in determining the origins of viruses and therefore defers to experts in this area, strongly supporting their funding for origin studies," said Murphy, who is also a lab coordinator at the Division of Biology and Biological Engineering of Caltech.

Another co-signer of the Science letter, Professor Michael Worobey, head of the Department of Ecology and Evolutionary Biology in the University of Arizona, also spoke out recently against misinterpretation of his viewpoints on the lab leak scenario.

On July 23, Worobey retweeted a post of Johns Hopkins Bloomberg School of Public Health, which voiced support for "an animal origin of SARS-CoV-2," saying that the reposting was to "explain why I (continue to) think that a zoonotic origin of SARS-CoV-2 is more likely than a lab leak scenario -- even though I signed 'The Science Letter'."

Meanwhile, he also reposted a report by The New York Times, titled A Group of Scientists Presses a Case Against the Lab Leak Theory of COVID, noting that he "wanted to clarify this since a couple of very good recent press articles may leave the impression that as a co-author of the Science letter I used to think the lab leak scenario was more likely."