The flu, short for influenza, is a common infectious disease characterized by congestion, fever, headaches, body aches, and exhaustion. It’s caused by the influenza virus, which has many different strains because of its ability to mutate, or change its RNA, in order to better reproduce itself.

This season, the strain running rampant is a Type A called H3N2, making up about 80% of flu cases in the U.S. as of January 8. It tends to hit the very young and the very old ends of the spectrum hard, much more than the (also Type A) H1N1 and the Type B strains.

Thanks to observations done of Australia’s flu season half a year ago—which U.S. immunologists study to predict what will happen in our own—this year’s flu vaccine included H3N2 in its mix of influenza viruses. However, the shot has been proving itself to be less effective than normal. This current season is rated as “moderately severe” and has been compared to the similarly severe season of 2014-2015, and overall in the country, about 22.7 out of 100,000 people with the flu have been hospitalized.

According to the CDC, 211 people in the U.S. have died of influenza this season as of December 23—27 of them were California residents younger than 65, compared to only 3 at around the same time the previous season. Many are speculating that the current flu season has simply peaked earlier than normal, while others are warning that all rates have been unusually high. Researchers are still trying to determine why this season has exceeded the severity of previous seasons.

But as all health professionals would recommend: don’t panic. Although this year’s flu may be alarming to read or hear about, many in the country will still be able to avoid the illness—and even more won’t have to worry about having to be hospitalized.

The best course of action is as normal a routine as any other season. Take basic precautions: avoid people who are already ill; wash your hands thoroughly and avoid touching your eyes, mouth, and nose; eat well, stay hydrated, and remain inside a warm building instead of spending too much time in cold weather.

Officials also recommend receiving the flu vaccine if you haven’t yet, despite the flu season being well underway. While the shot might not be able to prevent you from getting sick entirely, it has been proven to reduce the amount of time being sick and ease the severity of the symptoms. It especially reduces the risk of a child’s death, who is among the demographic most in danger of complications from the flu.

“Some protection is better than no protection,” said Dr. Randy Bergen, a pediatrician leading Kaiser Permanente-Northern California’s anti-flu effort. “But it’s certainly disappointing to have a vaccine that’s just not as effective as we’d like it to be.”

In the United States, flu vaccines are recommended for everyone six months or older. In the midst of this severe flu season, make sure to stay healthy and take basic precautions to avoid getting sick.