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Scientists debate how lethal COVID is. Some say it's now less risky than flu

A pharmacy in New York City offers vaccines for COVID-19 and flu. Some researchers argue that the two diseases may pose similar risks of dying for those infected.
Ted Shaffrey
/
AP
A pharmacy in New York City offers vaccines for COVID-19 and flu. Some researchers argue that the two diseases may pose similar risks of dying for those infected.

Has COVID-19 become no more dangerous than the flu for most people?

That's a question that scientists are debating as the country heads into a third pandemic winter. Early in the pandemic, COVID was estimated to be 10 times more lethal than the flu, fueling many people's fears.

"We have all been questioning, 'When does COVID look like influenza?''' says Dr. Monica Gandhi, an infectious disease specialist at the University of California, San Francisco. "And, I would say, 'Yes, we are there.'"

Gandhi and other researchers argue that most people today have enough immunity — gained from vaccination, infection or both — to protect them against getting seriously ill from COVID. And this is especially so since the omicron variant doesn't appear to make people as sick as earlier strains, Gandhi says.

So unless a more virulent variant emerges, COVID's menace has diminished considerably for most people, which means that they can go about their daily lives, says Gandhi, "in a way that you used to live with endemic seasonal flu."

But there's still plenty of differing views on this topic. While the threat from COVID-19 may be approaching the peril the flu poses, skeptics doubt it's hit that point yet.

"I'm sorry — I just disagree," says Dr. Anthony Fauci, the White House's medical adviser, and director of the National Institute of Allergy and Infectious Diseases. "The severity of one compared to the other is really quite stark. And the potential to kill of one versus the other is really quite stark."

COVID is still killing hundreds of people every day, which means more than 125,000 additional COVID deaths could occur over the next 12 months if deaths continue at that pace, Fauci notes. COVID-19 has already killed more than 1 million Americans and it was the third leading cause of death in 2021.

A bad flu season kills about 50,000 people.

"COVID is a much more serious public health issue than is influenza," Fauci says, noting this is especially true for older people, the group at the highest risk dying from the disease.

Debating the way deaths are counted

The debate over COVID's mortality rate hinges on what counts as a COVID-19 death. Gandhi and other researchers argue that the daily death toll attributed to COVID is exaggerated because many deaths blamed on the disease are actually from other causes. Some of the people who died for other reasons happened to also test positive for the coronavirus.

"We are now seeing consistently that more than 70% of our COVID hospitalizations are in that category," says Dr. Shira Doron, an infectious disease specialist at the Tufts Medical Center and a professor at the Tufts University School of Medicine. "If you're counting them all as hospitalizations, and then those people die and you count them all as COVID deaths, you are pretty dramatically overcounting."

If deaths were classified more accurately, then the daily death toll would be closer to the toll the flu takes during a typical season, Doron says. If this is true, the odds of a person dying if they get a COVID infection — what's called the case fatality rate — would be about the same as the flu now, which is estimated to be around 0.1%, or perhaps even lower.

In a new report from the Centers for Disease Control and Prevention published Thursday, researchers attempted to filter out other deaths to analyze mortality rates for people hospitalized "primarily for COVID-19." They find the death rate has dropped significantly in the omicron era, compared to the delta period.

But Fauci argues that it's difficult to distinguish between deaths that are caused "because of" COVID and those "with" COVID. The disease has been found to put stress on many systems of the body.

"What's the difference with someone who has mild congestive heart failure, goes into the hospital and gets COVID, and then dies from profound congestive heart failure?" he asks. "Is that with COVID or because of COVID? COVID certainly contributed to it."

A second reason many experts estimate that COVID's mortality rate is probably lower than it appears is that many infections aren't being reported now because of home testing.

The fatality rate is a ratio — the number of deaths over the number of confirmed cases — so if there are more actual cases, that means that the likelihood of an individual dying is lower.

"I believe that we have reached the point where, for an individual, COVID poses less of a risk of hospitalization and death than does influenza," Doron says.

Dr. Ashish Jha, the White House COVID-19 response coordinator, agrees, especially because the vaccines and treatments for COVID are better than those for the flu.

"If you are up-to-date on your vaccines today, and you avail yourself of the treatments, your chances of dying COVID are vanishingly rare and certainly much lower than your risk of getting into trouble with the flu," Jha told NPR.

Risk remains high for the elderly and frail

But Jha stresses that omicron is so contagious and is infecting so many people that it overall "on a population level poses a much greater threat to the American population than flu does," and it can still cause a greater number of total deaths.

And, mortality rates for any disease vary by age and other demographic factors. Importantly, COVID remains much more lethal for older and medically frail people than younger people. Recent data from the CDC shows that compared to 18- to 29-year-olds, people aged 65 to 74 have 60 times the risk of dying; those aged 75 to 84 have 140 times the risk; and those 85 and older have 330 times greater risk.

The danger is especially high for those not vaccinated, boosted and treated properly. And with COVID still spreading widely, they remain vulnerable to exposure from social contact.

While younger, otherwise healthy people can sometimes get very sick and even die from COVID, that's gotten rare.

"I think it's really important people have an accurate sense of the reality in order to go about their lives," says Dr. Jake Scott, an infectious disease specialist at Stanford University. "If their risk assessments are being driven by or influenced by these overestimated hospitalization and death rates, I think that's problematic."

Waiting to see if the pattern is confirmed

Other researchers still argue that COVID remains far riskier than the flu.

"However you slice it, there was never an instance where COVID-19 was milder than the flu," says Dr. Ziyad Al-Aly of Washington University in St. Louis, who has done research comparing COVID to the flu.

"We've never, ever in the history of the pandemic, in all our studies from the beginning until now, have found that COVID-19 is equally risky to the flu," Al-Aly says. "It's always carried a higher risk."

Some experts are waiting for more data that shows a clear trend in reduced mortality rates.

"I'll probably feel more comfortable saying something like, 'Oh, COVID is similar to the flu' when we actually see a pattern that resembles that," says Dr. Jeremy Faust, an emergency physician at Brigham and Women's Hospital in Boston in the division of health policy and public health. "We're sort of just starting to see that, and I haven't really seen that in a sustained way."

Many also point out that COVID can increase the risk of experiencing long-term health problems, such as long COVID.

"Even people with mild to moderate symptoms from COVID can end up with long COVID," Fauci says. "That doesn't happen with influenza. It's a totally different ball game."

But Gandhi also questions that. Much of the estimated risk for long COVID comes from people who got seriously ill at the start of the pandemic, she says. And if you account for that, the risk of long-term health problems may not be greater from COVID than from other viral infections like the flu, she says.

"It was really severe COVID that led to long COVID. And as the disease has become milder, we're seeing lower rates of long COVID," Gandhi says.

In fact, some experts even fear that this year's flu season could be more severe than this winter's COVID surge. After very mild or even nonexistent flu seasons during the pandemic, the flu hit Australia hard this year. And what happens in the Southern Hemisphere often predicts what happens in North America.

"If we have a serious influenza season, and if the omicron variants continue to cause principally mild disease, this coming winter could be a much worse flu season than COVID," says Dr. William Schaffner, an infectious disease researcher at Vanderbilt University.

Copyright 2022 NPR. To see more, visit https://www.npr.org.

Rob Stein is a correspondent and senior editor on NPR's science desk.