Newly released Slack messages suggest that some authors of a prominent 2020 paper on the origins of SARS-CoV-2 privately expressed doubts about the virus not originating from a lab, contrary to the paper's public conclusions. The documents were released by Sen. Rand Paul, R-Ky., a vocal critic of the U.S. government's handling of the COVID-19 origins investigation.
The paper, titled "The Proximal Origin of SARS-CoV-2," was published in Nature Medicine in March 2020 and was widely cited by public health officials and media outlets to support the theory that the virus originated naturally from bats. However, the released messages indicate internal discussions among the authors, including Kristian Andersen, Robert Garry, Eddie Holmes, and Andrew Rambaut, where the possibility of a laboratory origin was considered.
According to the documents, Andersen assigned a 30% probability to a lab origin, while Holmes estimated it at 20%, later revising it to 10%. These figures contrast with the paper's public statement that the virus had not been genetically manipulated.
In one message, Andersen wrote, "The part I’m really struggling with is that at the end of the day, we really don’t have any hard evidence one way or the other — and especially given some of the recent evidence, we also can’t rule out that somebody actually put it in there... Our paper was pretty strong in saying ‘there’s no way,’ but I have less confidence in that statement at this stage."
The messages also reveal internal debates regarding the furin cleavage site, a genetic feature central to the lab-leak hypothesis. Andersen reportedly conveyed to colleagues that certain findings made him "not comfortable" and reduced his confidence in the paper's definitive conclusions.
Sources indicate that the authors also coordinated with U.S. intelligence agencies and leadership at the National Institutes of Health (NIH) while publicly asserting their findings. The documents also touched upon internal dynamics with prominent coronavirus researcher Ralph Baric, including suspicions that he may have been an anonymous leaker who shared confidential peer-review information.
In a separate development highlighted by the release, documents also showed that U.S. Customs and Border Protection (CBP) agents were prepared to question Peter Daszak, former president of the EcoHealth Alliance and a researcher linked to the Wuhan Institute of Virology, upon his return to the United States. The FBI reportedly intervened and asked CBP agents to stand down from questioning Daszak, who had been involved with the World Health Organization's investigation into COVID-19 origins.
Dr. Anthony Fauci, a central figure in the U.S. pandemic response, is scheduled to testify before the Senate Homeland Security and Governmental Affairs Committee regarding the virus's origins. Paul, who chairs the committee, issued a subpoena for Fauci's testimony. Accusations have been made by some individuals claiming Fauci manipulated intelligence related to the pandemic's origins and misled Congress.