“The most likely explanation is a natural evolution from an animal reservoir to a human,” Fauci, the director of the National Institute of Allergy and Infectious Diseases, told CNN’s Jim Acosta.
“Once you say that, which I believe is the more likely, you’ve got to make sure you emphasize that you still keep an open mind for all possibilities, including a lab leak,” he added.
Acosta pressed Fauci to confirm he believes the natural origins theory is still the more likely scenario.
“I do, right, and I’m not alone in that,” Fauci said. “A recent paper was put out by 21 very well internationally-respected virologists and evolutionary biologists who said the same thing as I’m saying. And I rely on people like that, who have great experience in this. That’s what they do every single day — who, again, are open minded — and are saying it’s conceivable that you may have had a lab leak. So you’ve got to keep an open mind to all possibilities, but they feel that the more likely explanation is a natural evolution from an animal host to a human.”
Dr. Paul Offit, a prominent member of the US Food and Drug Administration’s vaccine advisory committee, echoed Fauci’s confidence in the natural origins theory Saturday.
“I think the chance that this was created by laboratory workers — that it was engineered — is zero,” Offit told Acosta in a separate interview.
Current intelligence reinforces the belief that the virus most likely originated naturally, from animal-human contact, and was not deliberately engineered, the sources said. But that does not preclude the possibility that the virus was accidentally leaked from the Wuhan Institute of Virology, where coronavirus research was being conducted on bats — although many scientists familiar with the research say such a leak is unlikely.
Natasha Bertrand, Pamela Brown, Katie Bo Williams and Zachary Cohen contributed to this report.