Authors of a paper that dismissed the theory that COVID-19 came from a laboratory said months after the paper was published that it was possible COVID-19 came from a lab, according to newly released messages.
“Gotta say – some smoking(ish) guns starting to appear that I’m not comfortable with,” Kristian Andersen, one of the authors and a professor at Scripps Research, wrote in a Slack message on June 11, 2020.
He was responding to a social media post that outlined research in 2006 on inserting a characteristic, a furin cleavage site, at the exact place where the cleavage site was in the virus that causes COVID-19. The virus is known as SARS-CoV-2.
“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,” Andersen added later.
Andersen and others wrote a paper called “The Proximal Origin of SARS-CoV-2” earlier in 2020. The authors said in the paper that their analyses “clearly show that SARS-CoV-2 is not a laboratory construct or a purposefully manipulated virus” and that no lab-based scenario was plausible.
“The authors publicly said there was ‘no evidence’ SARS-CoV-2 was engineered,” Sen. Rand Paul (R-Ky.) said in a statement on July 21. “Privately, Kristian Andersen put the odds of a lab leak at 30%. Eddie Holmes estimated 20% — later revised down to 10%. Those aren’t zero.”
Paul, the chairman of the Senate Committee on Homeland Security and Governmental Affairs, released the Slack messages.
Andersen said in several of the messages that the proximal origin paper contained mistakes. For instance, the authors said in the paper that work on bat coronaviruses was performed “across the world.”
“That isn’t true,” Andersen wrote. “It has exclusively been going on at WIV,” referring to the Wuhan Institute of Virology.
Andersen wrote in other messages in June 2020 that some new evidence on the origins of SARS-CoV-2 was “peculiar,” that he had shifted to believing lab and natural origins were “equally probable,” and that, “Our paper was pretty strong in saying ‘there’s no way,’ but I have less confidence in that statement at this stage.” He also said that the chances of a lab origin were 30 percent, while Holmes, a professor at the University of Sydney, pegged them at 20 percent, before revising that estimate to 10 percent.
Andersen and Holmes did not respond to requests for comment by publication time.
Some Slack messages between the authors from earlier in 2020 were previously made public, including a message from April 2020 in which Andersen said that they could not “fully rule out engineering,” or creation of the virus. Nature Medicine, which published the proximal origin paper, has declined to retract or otherwise adjust the paper, which is one of the most popular papers in history and was promoted by top U.S. government officials.
Andersen told lawmakers during a hearing in Washington following the previous release that a closer review of evidence led the authors to rule out a lab origin.
Grant Proposal
Some of the messages came after a previously unknown proposal to conduct risky research was released in 2021 by a group called the Decentralized Radical Autonomous Search Team Investigating COVID-19.
The document, written by U.S.-based EcoHealth Alliance, which funneled money to the Wuhan Institute of Virology, proposed carrying out research to insert a furin cleavage site into coronavirus clones.
“It really isn’t beyond plausibility that someone went ahead and tried some of this stuff,” Andrew Rambaut, one of the authors of the proximal origin paper and a biology professor at the University of Edinburgh, wrote in a message on Sept. 21, 2021, after the document was made public. “We just need to re-convince ourselves it is coincidence.”
Rambaut did not respond to a request for comment.
“We still have no evidence for [SARS-CoV-2] in that lab and they must have sequenced it first,” Holmes wrote later that day. “But it is very striking that a bat-derived [coronavirus] with [a furin cleavage site] turns up in a city that was on a grant proposing to muck around with [furin cleavage sites] in bat-derived [coronaviruses].”
Andersen said that “we can’t ignore this” and that he needed to “get something back” to the National Institutes of Health and Dr. Anthony Fauci, a top official at the institutes at the time who had secretly helped with the proximal origin paper.
Peter Daszak, the president of EcoHealth at the time, told members of Congress in 2024 that he believed the work outlined in the proposal had not been done, but that he could not confirm whether Wuhan researchers had started the experiments. At least some of the research was proposed to take place at the Wuhan lab, although the Defense Advanced Research Projects Agency declined to fund the proposal due to concerns about the impact of adding features to coronaviruses.
Andersen and the others said they would analyze different parts of the grant proposal.
“Stay off email,” Rambaut told the others. “Or carefully curate some emails for the [Freedom of Information] records.”