Public health officials have warned Americans to prepare for the spread of the novel coronavirus in the U.S., but the better-known flu virus is a far greater threat to Americans’ health right now, data from the Centers for Disease Control and Prevention suggest.

President Donald Trump, seeking to reassure Americans about the novel coronavirus at a Wednesday press conference, said he was “shocked” to learn that the flu kills “from 25,000 people to 69,000 people a year.” So far this flu season, 16,000 Americans have died from flu, according to the CDC.

As of Thursday, there were 82,549 confirmed cases of coronavirus worldwide and at least 2,810 deaths, according to the latest figures from health officials. The illness has now spread to more than 40 countries. A person in California who tested positive for the illness despite having not recently traveled to China was thought to be the first case of “community spread” in the U.S.

“ Americans have simply gotten used to influenza despite the staggering number of people it affects. ”

There were 60 confirmed cases in the U.S. as of Thursday, according to the Centers for Disease Control and Prevention.

The CDC has called this coronavirus “a very serious public health threat,” but adds that its immediate health risk to the American public is low. Health officials remain uncertain of exactly how the coronavirus spreads.

In contrast, at least 29 million people in the U.S. have experienced flu illnesses this season, the CDC estimates. About 280,000 people have been hospitalized so far, and an estimated 16,000 have died, including 105 children.

Americans have simply gotten used to influenza despite the staggering number of people it affects, said Scott Weisenberg, a clinical associate professor of medicine and director of NYU Langone Health’s travel medicine program.

“With influenza, it’s fairly predictable: We see a fairly consistent number of individuals, sometimes higher, sometimes lower,” he told MarketWatch earlier this month. Coronavirus, on the other hand, “went from having zero cases” to a large number of cases in China and an emerging number of cases worldwide, he said. “We don’t know where it’s going to end up.”

Influenza “remains a dangerous virus every single year,” Weisenberg added. Groups at high risk for flu-related complications include adults aged 65 and over; pregnant women; young kids and children with neurological conditions; people living with conditions like diabetes, asthma, cancer, HIV/AIDS, and heart disease; and people who have had a stroke.

“ 29 million people in the U.S. have experienced flu illnesses this season, and an estimated 16,000 have died. 105 children have died this flu season. ”

Children’s and young adults’ hospitalization rates are currently higher than those observed at this time in recent flu seasons, the CDC says, despite overall flu hospitalization rates staying around the same level. More than half of specimens that tested positive for influenza this season have been in people younger than 25.

Influenza B, which impacts young people more severely, has been reported more often this season on a national level, according to the CDC’s most recent flu-surveillance report. But influenza A’s H1N1 subtype has been more commonly reported in recent weeks.

For everyone six months and older, the CDC says getting the yearly flu vaccine is “the single best way” to ward off the seasonal flu virus. People should also steer clear of close contact with sick people; stay home from work and school when they’re sick; cover their mouth and nose while sneezing or coughing; and clean their hands with soap and water or an alcohol-based sanitizer, the CDC says.

Just 45% of U.S. adults last flu season received a flu vaccine, according to Health and Human Services Secretary Alex Azar. Almost 63% of kids got a vaccine.

The CDC says estimates of this season’s flu-vaccine effectiveness aren’t yet available, but it notes that research shows the flu vaccine typically reduces risk of flu illness by 40% to 60% when the vaccine viruses are similar to the ones currently circulating.

And while the CDC regularly publishes information on flu illnesses, hospitalizations and deaths that can be analyzed and compared year to year, health experts know far less about the new coronavirus, Weisenberg added — including the number of people with milder virus symptoms who could still transmit it to other people.

Nancy Messonnier, the director of the CDC’s National Center for Immunization and Respiratory Diseases, told reporters Tuesday that the agency wanted to brace Americans “for the possibility that their lives will be disrupted” by the novel coronavirus. Later that day, Azar added: “We hope that we don’t face those kinds of eventualities, but transparency is being candid with people.”

“The data over the last week and the spread in other countries has certainly raised our level of concern and raised our level of expectation that we are going to have community spread here,” Messonnier said Wednesday. “That’s why we are asking folks in every sector as well as people within their families to start planning for this.”

In a recent report, the CDC noted that the coronavirus’s symptoms (which include cough and fever) were similar to flu symptoms, and that the coronavirus outbreak coincided with a season that brings a heightened prevalence of respiratory illnesses.

“Reducing the number of persons in the United States with seasonal influenza will reduce possible confusion with 2019-nCoV infection and possible additional risk to patients with seasonal influenza,” the agency said.

(This story was updated with new coronavirus figures on Feb. 27.)