Dr. Robert Redfield, the former director of the Centers for Disease Control and Prevention (CDC), says that he believes the novel coronavirus escaped from a lab in Wuhan, according to news reports. However, many experts have rejected that theory as unlikely.
In an interview with CNN released Friday (March 26), Redfield stressed that this was his "opinion" on the origins of the virus, and he did not cite any evidence for that theory. "I'm allowed to have opinions now," he said.
"I'm of the point of view that I still think the most likely etiology of this pathogen in Wuhan was from a laboratory, you know, escaped," Redfield told CNN's Dr. Sanjay Gupta. "Other people don't believe that, that's fine. Science will eventually figure it out."
The origins of SARS-CoV-2, the virus that causes COVID-19, have been hotly debated, and some experts have said we may never know exactly where the virus came from, Live Science previously reported. The idea that the virus emerged from a lab arose early on in the pandemic, when people noted that a high-security biolab in Wuhan, the Wuhan Institute of Virology (WIV), was studying coronaviruses.
Still, a number of scientists say the most likely explanation is that the virus emerged naturally, passing from bats to another animal and then to humans, Live Science previously reported. Recently, a team from the World Health Organization, which is investigating the origins of SARS-CoV-2, said that it agrees with this hypothesis — WHO officials said the virus likely passed from bats to animals on wildlife farms in China, and then to humans, Live Science previously reported.
Redfield said he didn't believe the bat theory. "Normally, when a pathogen goes from a zoonosis to humans, it takes a while for it to figure out how to become more and more efficient in human-to-human transmission," Redfield told CNN. "I just don't think this makes biological sense."
The former CDC chief wasn't suggesting SARS-CoV-2 is an engineered virus — another theory with no supporting evidence — just a natural escapee. "In the lab, you think that that process of becoming more efficient was happening?" Gupta asked.
"Yeah, let's just say I have coronavirus that I'm working on. Most of us in the lab, we're trying to grow a virus, we try to help make it grow better and better and better … so we can do experiments," Redfield responded.
But some experts have noted that the SARS-CoV-2 genome is genetically different from other coronaviruses that were being studied in the Wuhan lab in important ways.
"The SARS-CoV-2 virus has some key differences in specific genes relative to previously identified coronaviruses — the ones a laboratory would be working with," Dr. Adam Lauring, an associate professor of microbiology, immunology and infectious diseases at the University of Michigan Medical School, told Live Science in April 2020. "This constellation of changes makes it unlikely that it is the result of a laboratory 'escape'."
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, responded to Redfield's comments, telling CNN, "Obviously, there are a number of theories … Dr. Redfield was mentioning that he was giving an opinion as to a possibility, but again, there are other alternatives — others, that most people hold by."
Originally published on Live Science.