Is Covid a thing of the past? Flu is back to being the most common winter ailment

Flu is outpacing Covid in the U.S. for the second consecutive winter, raising questions about America’s future with the respiratory illness.

While an estimated 25 million Americans have been stricken with flu since the season’s October start, only between three and nine million have contracted Covid during that same time frame, according to data from the Centers for Disease Control and Prevention.

At least 330,000 adults and children have been hospitalized for flu, with between 96,000 and 170,000 hospitalized for Covid. The number of deaths from Covid and flu since October is similar: the estimates for flu deaths are between 10,000 and 30,000, while the estimate for Covid deaths is 20,000.

Covid has continued to mutate and spread since the World Health Organization declared an end to the public health emergency in mid-2023 – though many infections are milder than at the pandemic’s start. Experts say Covid is now considered endemic, meaning the virus is constantly present.

Still, what Covid will look like for the U.S. this year remains unclear.

“We don’t know where Covid is going. I really don’t think we know what is the next season going to look like,” Manisha Juthani, Connecticut’s top public health official, told The Washington Post on Wednesday.

Some clues may lie in past Covid surges.

Last year, doctors suggested that a milder winter was due to an influx of Covid cases in summer 2024, during which people built up immunity to infection. Previously, cases had also spiked in the winter, as is typical for most respiratory illnesses when people head indoors.

“Overall, the severity of Covid is much lower than it was a year ago and two years ago. That’s not because the variants are less robust. It’s because the immune responses are higher,” Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston, told NBC News.

Research from Stanford Medicine tied milder Covid symptoms to prior run-ins with other coronaviruses, too.

Another potential reason may be that flu is pushing out Covid.

“There’s a lot of influenza circulating. It may generate some non-specific immunity – some nonspecific protection, which then prevents people from getting other respiratory infections, such as SARS-CoV-2 – sort of crowds it out,” Aubree Gordon, an epidemiologist at the University of Michigan School of Public Health, told NPR, referring to the virus responsible for Covid.

The past two flu seasons have been historically bad: the worst in decades. This year, there was a surprise mutation that emerged after vaccines were produced, although the vaccines continue to offer a fair amount of protection.

Covid has not mutated in a way that would shutter hospitals and force restrictions over the course of the last two years.

The hope is that this trend continues, with vaccines offering protection from year to year. Studies show that Covid vaccines protect people from death for all causes and reduce the risk of debilitating long Covid. Covid has killed more than one million Americans.

However, fewer people are getting Covid vaccines, with vaccination rates of adults aged 65 and older falling by nine percent since last year. The level of flu vaccinations is about the same as in 2025, CDC data shows.

The Trump administration has moved to halt Biden-era contracts aimed at developing more protective shots and limited Covid vaccine recommendations for children and pregnant women. And, it’s pulled out of the World Health Organization: the United Nations body that addresses pandemic response.

Last month, the WHO urged all governments not to drop the ball on pandemic prevention and preparedness.

“Funding continues to shift away from health toward defense and national security – placing at risk the very systems that were strengthened during Covid-19 to protect countries from future pandemics,” the organization said. “This is shortsighted. Pandemics are national security threats.”