Experts at the Centers for Disease Control and Prevention (CDC) recently announced that more than 80,000 Americans died of the flu during the 2017-18 season. Federal health officials said this was the highest number in more than a decade. 90 percent of the deaths were in people over age 65, but the flu also killed 180 children and teenagers.

The CDC does not count adult flu deaths directly, but estimates them based on the number of excess deaths during the flu season. Officials at the National Foundation for Infectious Disease (NFID) estimate that a record-breaking 900,000 people were hospitalized.

"Last season illustrated what every public health official knows — influenza can be serious in people of all ages, even in the healthiest children and adults," U.S. Surgeon General Jerome M. Adams, M.D., M.P.H., said in a press release. "It is critical that we focus national attention on the importance of influenza vaccination to protect as many people as possible every season."

The high mortality rate was unusual because it was caused by a "normal" — although severe — flu season instead of a new pandemic influenza strain like what occurred during the 2009-10 swine flu epidemic.

The dominant strain last season was an H3N2 flu, and the vaccine was only about 40 percent effective at preventing infection. According to the CDC, this is the same as in previous seasons.

The CDC recommends that almost everyone over the age of six months get a flu vaccine each year. Just 48.6 percent of the public was vaccinated last year, and 58 percent of children 17 and under were vaccinated. The CDC said the number of children age 4 and under who got a flu shot fell by 2 percent compared to the year before.

College students are among the least vaccinated. The NFID sponsored a survey of college students, and found that only between 8 and 39 percent of students get the vaccine, leaving that population at a particularly high risk of getting and spreading the virus.

Why do people opt out of the vaccine?

There are various reasons why many people say no to the vaccine. Some say they are healthy and don’t need it, while others cite a fear of needles.

The truth remains that if you are unvaccinated, you are vulnerable. Healthy people die from the flu every year and according to a recent study, the virus can even trigger a heart attack.

Getting a flu shot helps protect others from getting stick. According the CDC, people are contagious a full day before they start showing symptoms.

An extremely common complaint is among people who did get the vaccine and still got sick. It’s true that the shot doesn’t offer complete protection, but the CDC estimates that it reduces the risk of the virus by 40 to 60 percent. In other words, you may still get sick, but you probably won’t get as sick as you would without the vaccine.

Probably the most common misconception is the idea that you can get the flu from the flu shot. The flu vaccine is an inactivated virus, meaning that the vaccine can’t actually infect you.

William Schaffner, medical director at the NFID, says the most common side effects are a sore arm and a little swelling of the arm. A very small percent of people will run a fever after receiving the vaccine, but that’s the body reacting to the vaccine; it’s not the flu. Keep in mind that it does take one to two weeks for your immune system to protect you from the flu.

As many as 168 million flu vaccine doses will be available for the 2018-19 flu season. There are special vaccines for the elderly and for children, including egg-free versions.

Flu season has arrived. Now is the time to protect yourself.