If you think that because it’s February and you haven’t gotten the flu yet you’re in the clear, think again.

Flu is hitting the U.S. hard this season, and experts warn that it’s far from over.

According to the Centers for Disease Control and Prevention, doctors’ visits for flu-like symptoms — fevers, sore throat, extreme fatigue and body aches — have hit the highest level in nearly 30 years.

So far, this flu season has produced the highest number of cases in more than 30 years, with about 11 million infections reported by the CDC.

Those cases have led to roughly 120,000 hospitalizations and 5,000 deaths, including nine children. And the numbers are expected to keep climbing, since flu season typically lasts through April.

Currently, 45 states are experiencing high to very high levels of flu activity.

The dominant strain this season is a variant of influenza A (H3N2) known as the “subclade K” strain, often referred to as a “super flu” because of how rapidly it is spreading. This strain has been linked to more severe symptoms and higher rates of serious illness and hospitalization compared with a typical flu season.

Although this year’s flu vaccine is not a perfect match for the subclade K strain, experts stress that vaccination still provides important protection and can reduce the risk of severe illness.

Dr. Thomas Russo, chief of infectious diseases at the University at Buffalo School of Medicine in New York, says flu prevention should still rely on proven strategies.

“The ideal flu-prevention program is getting your flu shot — yes, even now, because flu season doesn’t end until April or May — and wearing a mask in crowded indoor settings,” Russo says.

The CDC recommends that everyone six months of age and older receive an annual flu vaccine. Most people hospitalized with flu are unvaccinated. During the 2019–2020 flu season, vaccination prevented an estimated 7 million illnesses, 3 million medical visits, 100,000 hospitalizations, and 7,000 deaths.

If symptoms such as fever, chills, sore throat, cough, congestion, body aches, or extreme fatigue come on suddenly, you may have the flu. Stay home, avoid contact with others, and contact your healthcare provider promptly.