The 2017-2018 flu season—which is peaking right now—is shaping up to be a severe one, officials announced this week.

“We are currently in the midst of a very active flu season,” said Centers for Disease Control and Prevention director Brenda Fitzgerald, M.D., who spoke at a media briefing today. Much of the country is experiencing “widespread and intense flu activity,” she said.

More About the Flu

The announcement confirmed earlier predictions. Experts had suspected that the flu season in Australia, which peaked in mid-August and was especially severe, might herald a bad season in North America as well. (Austrialia is often seen as an indicator of how the flu might play out in the U.S., explains Jeffrey Shaman, Ph.D., an associate professor in the department of environmental health sciences and director of Columbia University’s Climate and Health Program.)

Here in the States, during the first week of 2018, people were being hospitalized for flu at a rate of 22.7 per 100,000 people. That’s up from just 12.2 hospitalizations per 100,000 people during the same week last year.

Here’s what we know about this flu season, and what you can do to protect yourself.

Why Is This Flu Season Severe?

Preliminary estimates by the Australian government show that a virulent strain of influenza called H3N2 was most responsible for Australia’s unusually high number of flu cases, which resulted in 29,000 hospitalizations and 745 deaths in 2017, more than twice as many as the average over the previous five years.

According to the CDC, H3N2 is causing most of the cases of the flu in the U.S. right now as well. We know from past years that this strain is associated with more cases of the flu, more hospitalizations, and more deaths than other strains, according to Dan Jernigan, M.D., M.P.H., director of CDC’s influenza division, who also spoke during the media briefing.

Evidence shows that the Australian flu vaccine, which is largely the same as the U.S. one, was only 10 percent effective against H3N2, according to a 2018 New England Journal of Medicine analysis. (The vaccine may end up having a slightly better track record against H3N2 in the U.S., according to early data—though not by much.)

That doesn't mean you shouldn't get a flu shot, however.

"While each flu season may have a dominant strain, there are other strains of the virus that will circulate as well," says William Schaffner, M.D., an infectious disease specialist at Vanderbilt University in Nashville and medical director of the National Foundation for Infectious Diseases. "We know that this vaccine was quite good on the other strains.”  

Plus, when people who are vaccinated do get the flu, it tends to be milder and less contagious, Schaffner adds.

Jernigan says that it looks like flu season is peaking “right about now.” But he says that’s no reason not to get vaccinated if you haven’t yet. “We have a lot more flu to go,” he says.

How to Protect Yourself From the Flu

According to data released by the CDC, about 3 in 5 Americans had not gotten their flu shots as of December 7. Meanwhile, though flu activity was low in October, it's been rising steadily since the beginning of November, and it spiked sharply in December.

It's still not too late to protect yourself. Just remember that it can take up to two weeks after you've had your shot for your immunity to kick in.

In addition to getting the flu vaccine, our medical experts offers these three tips for avoiding germs this time of year:

1. Because dry air helps the flu virus live longer, consider using a humidifier to keep humidity at 30 to 50 percent.

2. Avoid touching your nose and eyes, to reduce the chance of transferring any virus you might have on your hands.

3. Wash your hands often. Use soap and water, and rub hands together for at least 20 seconds. When soap and water are not available, use a hand sanitizer with at least 60 percent alcohol.

What to Do If You Get the Flu

Rest, keep yourself hydrated, and if you have fever, headache, and achiness, opt for acetaminophen (Tylenol and generic), ibuprofen (Advil and generic), or naproxen (Aleve and generic).

Ask your doctor for a prescription for an antiviral medication right away if you develop a fever, cough, and body aches and you’re 65 or older, obese, or have a compromised immune system or a chronic health concern. Your pediatrician might recommend antivirals for children who have severe flu or chronic health conditions like asthma, diabetes, or heart or lung disease.

An antiviral medication can shorten the flu by one to three days, ease symptoms, and cut the risk of complications, but only if you start it within 48 hours of getting sick.

Jernigan notes that while the overall supply of antiviral flu medication should be sufficient to last through the season, some areas with a lot of flu may be short on the medication. “Individual patients seeking to fill an influenza antiviral prescription may want to call ahead to their pharmacy and make sure the product is on the shelf,” he says.

Avoid cough suppressants (flu coughs usually go away on their own) and antibiotics, which don’t work for viral infections and can contribute to antibiotic-resistant bacteria.

See your doctor if your flu symptoms start to improve but then fever returns and your cough worsens, or if you experience difficulty breathing, pain in the chest or abdomen, dizziness or confusion, and severe or persistent vomiting. 

For more treatment tips, see our guide to treating cold and flu symptoms.