If you skipped this year’s flu shot and then came down with the virus, you may think there’s no point to getting the vaccine now.

But you’d be wrong.

There are good reasons to get a flu shot, even if you’ve already been sick, says David Topham, Ph.D., professor of microbiology and immunology at the University of Rochester and director of the New York Influenza Center of Excellence.

More on flu season

You can catch the flu more than once in a season—because having one “type” of flu doesn’t provide immunity against the other types that may be circulating. 

“The way your immune system sees them is very different,” Topham says.

Two types commonly make people ill: type A and type B. This flu season, as is typical, most cases of flu so far have been type A (the H3N2 strain).

But at this point in the season, it looks like type A flu may be beginning to wane, Topham says, while influenza B may be on the rise.

And though flu season may be peaking in some areas of the country, it’s far from over. There are probably at least several more weeks of high flu activity to come, according to the Centers for Disease Control and Prevention.

A Second Flu Can Be as Bad as the First

Getting the flu a second time can make you just as miserable as it did the first time around, says Marvin M. Lipman, M.D., Consumer Reports’ chief medical adviser.

“And the potential for complications with the second infection is just as great as it was with the first,” Lipman says.

Those complications can be serious, such as pneumonia and even sepsis, a potentially deadly reaction your body can have to infection.

Flu can also harm your heart: A study published this week in the New England Journal of Medicine found that an individual’s heart attack risk was six times higher than usual in the seven days following a positive test for influenza. 

This may be of most concern to older adults, especially those with heart disease or who are at higher risk for heart disease because of smoking, diabetes, or other factors, says Jeff Kwong, M.D., lead author of the study and a scientist at the Institute for Clinical Evaluative Sciences in Ontario.

So Get That Flu Shot

The bottom line: If you haven’t had one yet, get a flu shot, even if you already had the flu (or a bug you think might have been the flu). Although the vaccine doesn’t guarantee that you’ll avoid a second case of the flu, it will reduce the likelihood of it and its complications.

And if you did get the vaccine this season, there’s no need to get a second one—scientists believe the protection usually lasts for the whole season.

But if you’re still getting over a respiratory illness—or any kind of bug—wait until you’re fully recovered before going for the flu shot, says Topham at the University of Rochester. When you have another illness, he says, “your immune system is focused on the infection that you have and doesn’t respond as well to a vaccine.”

And keep in mind that if you’re starting to recover from the flu and symptoms worsen again, this could signal a secondary infection such as pneumonia and you should call your doctor right away.

Your hygiene habits can also help stop the spread of flu. Remember to be diligent about washing your hands and covering any coughs or sneezes. Avoid touching your eyes and mouth to keep from transferring any germs that may be on your hands. Keeping air at 30 to 50 percent humidity by using a humidifier can help, too; dry air helps the flu virus live longer.

If you do get sick again, stay home to avoid infecting anyone else.