scorecardresearch Skip to main content

‘We may not ever know’: Fauci says origin of coronavirus could remain a mystery

Dr. Anthony Fauci, former director of the National Institute of Allergy and Infectious Diseases, at the White House last November.Patrick Semansky/Associated Press

The pandemic’s true origin may never be uncovered, despite a new assessment favoring the lab leak theory from the US Department of Energy, said Dr. Anthony Fauci, former director of the National Institute of Allergy and Infectious Diseases, on Monday.

The energy department’s conclusion, first reported on Sunday by The Wall Street Journal, shows that there remains “a dichotomy of opinion” among experts but doesn’t firmly answer the question, Fauci said in an interview at the Globe’s first Health and Biotech Week event.

Based on new but undisclosed evidence, and with “low confidence,” the agency concluded the virus was probably leaked by accident from a laboratory in Wuhan, China. The FBI reached a similar conclusion in 2021, with “moderate confidence.”


But Fauci, stressing the importance of keeping “an open mind,” noted that four other intelligence agencies don’t buy the lab leak theory.

Meanwhile, evolutionary virologists have published two peer-reviewed articles showing biological evidence that “rather strongly suggests it was a natural occurrence,” he said. These virologists, using DNA evidence, demonstrated that the virus probably jumped from animals to people at a live-animal market in Wuhan.

Asked whether investigators will find a definitive answer, Fauci said, “We may not ever know.”

The “fireside chat” between Fauci and Anna Kuchment, the Globe’s medical and biotechnology editor, was the first event in the Globe’s series of online seminars celebrating advances in science and technology. In December, Fauci stepped down as NIAID chief and also as President Biden’s chief medical adviser.

As for the state of the pandemic now, Fauci said, “The good news is that we’re much better off than we were a year ago. The sobering news is that we’re not out of the woods yet.” He called the current rate of 400 to 500 COVID-19 deaths in the United States per day “unacceptably high.”


That poor record reflects low rates of vaccination, as well as the failure to take reasonable precautions like masking in crowded indoor places and testing when symptoms are present, he said.

When will COVID-19 recede? “That’s up to us,” he said. “It’s totally up to us.”

In response to an audience question, Fauci said the decision to wear a mask comes down to evaluating the level of infection in the region one is in, and one’s willingness to take risks. “There is no one rule that stands for every person in every particular place,” he said.

As an 82-year-old, Fauci himself is in a high-risk group, but he also has good immunity from one infection and multiple vaccinations, he said. Still, if he’s in a crowded place in an area with a high prevalence of COVID-19, he will wear a mask.

“But I’m not wed to a mask at every indoor setting I go to,” he said. “I’m careful, but not to an extent that it inhibits greatly what I’m doing.”

Turning to the next public health threat, Fauci discussed the H5N1 influenza virus circulating among fowl and recently detected in mammals. “Could that be our next pandemic?” Kuchment asked.

“Certainly it can,” Fauci replied. “It is a threat. It’s real.”

Although bird flu has been present for decades, the fact that it has now jumped to minks, seals, and other mammals is particularly disturbing, he said, because it could next adapt to humans.


“Yes, the short answer to your question is, we need to pay attention to it because it could be a threat for the next pandemic.”

Asked to assess the response to the COVID-19 pandemic, Fauci said the scientific response was “a resounding success,” with the fast development of effective vaccines and treatments. But the public health response faltered, lacking 21st-century infrastructure needed to track the virus in real time, he said.

As for the disinformation that also hampered the public health effort, scientists need to step up and “be out there more talking about true data, and true evidence-based information as opposed to the distortion and misinformation that seems to be so prevalent these days,” Fauci said.

He intends to be among them, even though he continues to face threats from right-wing extremists and conspiracy theorists.

“I’m going to be writing and lecturing and getting involved in different groups,” he said. “I will very likely be associated with an organization sometime soon.” He also intends to write a memoir and hopes his writing and public appearances will inspire young people to pursue science, public health, and public service.

After leading NIAID for nearly 40 years, Fauci said, “I wanted to step down when I still had a few more years when I’m energetic, I’m passionate, I’m enthusiastic about doing new things, and thank goodness, I’m healthy and able to do that.”

The Globe’s Health and Biotech Week features free online seminars at noon each day this week. To register, go to


Felice J. Freyer can be reached at Follow her @felicejfreyer.