Flu levels are rising once again across the United States, with emergency department visits increasing among children older than 5, according to data from the Centers for Disease Control and Prevention.

The situation is not nearly as bad as in December, when emergency rooms were flooded with sick patients. But doctors say that we are likely to see a second, smaller rise in cases in the weeks ahead, which tends to happen every year in late winter, and that the virus will continue to spread into the spring.

“It’s certainly gone down. It’s not gone by any means,” said Dr. Michelle Barron, a professor of infectious diseases at the University of Colorado Anschutz.

What Do We Know About the Flu Viruses Spreading Right Now?

Every year, two types of flu circulate in the United States: influenza A and then, typically later in the season, influenza B.

This season, a new variant of influenza A has spread widely, in part because it is adept at evading immunity from vaccinations or previous infections. It has been particularly severe for young children, leading to more hospitalizations and emergency room visits than doctors would expect in a typical flu season.

Dr. Zachary Binder, a pediatric emergency medicine physician at UMass Memorial Medical Center, said that many of the patients he saw during the December wave developed serious symptoms, including extremely high fevers, seizures and dehydration.

Now, influenza B cases are starting to pick up. That’s normal around this time of year and suggests cases will climb in the coming weeks, said Scott Hensley, a professor of microbiology at the University of Pennsylvania Perelman School of Medicine who studies the flu.

Influenza A and influenza B share the same symptoms, including fever, chills, aches and fatigue, as well as a cough, sore throat and nausea. They tend to lead to similar rates of hospitalizations and deaths in adults, but influenza B has been associated with higher rates of mortality in children.

What Can I Do to Avoid the Flu?

A flu shot can’t guarantee that you won’t get infected, but it can help you avoid some of the most serious outcomes.

“It’s pretty darn good at preventing you from being in the hospital, from dying of flu or from being truly miserable for two weeks, as opposed to three days,” said Dr. Bruce Farber, chief public health and epidemiology officer at Northwell Health.

Ideally, doctors said, people would already have been vaccinated heading into flu season. It isn’t too late to get the shot now, though, especially if you’re at high risk. It takes about two weeks to provide full protection.

Researchers had feared that this year’s flu shot would be ineffective against the new variant. While there is still a mismatch between the shot and that variant, emerging data shows that the flu vaccine does still provide significant protection against the worst outcomes from the flu.

Beyond vaccination, experts recommend common sense precautions: Frequently wash your hands; disinfect objects that you touch a lot, like doorknobs and phones; and improve ventilation by running an air purifier or opening a window.

Staying hydrated can also help keep your skin and the mucus membranes in your airways intact, Barron said. When dryness causes the inside of the nose to bleed, or the lips to crack, that gives the virus opportunities to enter and infect, she said.

Doctors also urged people to stay home if they feel sick, though infected people can spread the virus even before they feel ill. People can be contagious the day before they develop symptoms.

Those who are 65 or older, who are pregnant or who have compromised immune systems are at higher risk for serious illness. Dr. Sam Torbati, an emergency medicine doctor at Cedars-Sinai Emergency Room in Los Angeles, said he had seen many more flu patients this season than he typically does developing complications like bacterial pneumonia. An infection also dramatically raises the risk of heart attack or stroke, especially for those who have underlying heart issues.

If you are high risk and have been exposed to the flu, get in touch with your doctor, Barron said, even if you don’t feel sick yet. Your physician may preventively prescribe Tamiflu, an antiviral that can help people recover faster from the virus.

—

This article originally appeared in The New York Times.

By Dani Blum/Laila Stevens
c. 2026 The New York Times Company