If you've ever had the flu, you know how bad it can make you feel. To help avoid all that misery — as well as possible health complications — doctors now recommend that all teens through age 18 get a flu vaccine every year.

Hate getting shots? There's good news: The flu vaccine also comes in a nasal spray.

Why Get Vaccinated?

The main reason for getting vaccinated is to spare yourself the misery of flu. But there are other reasons to get vaccinated too.

It's especially important for people with certain medical conditions (like kidney disease, diabetes, HIV, heart problems, or asthma) to get a flu vaccine. They are more likely to get serious complications (like pneumonia) when they get the flu.

Kids and teens who take aspirin regularly also need to be vaccinated. They are at risk for developing a serious condition called Reye syndrome if they get the flu.

Another reason for getting vaccinated is to protect the people around you who might get seriously ill from flu — like babies, people with serious illnesses, and the elderly. When you protect yourself with a flu vaccine, you also protect other people who are more vulnerable because there's less chance you'll get the flu and pass it on. Scientists call this "herd immunity."

When Should a Person Get Vaccinated?

The best time to get a flu shot in the United States is before flu season starts. This gives the body a chance to build up immunity before the winter flu season. So you'll want to get vaccinated as soon as this year's flu vaccine becomes available in your area. (Your mom or dad should be able to find out when that is from your doctor's office, or ask your school nurse.)

If you can't get vaccinated right away, you can still get a flu shot throughout flu season and have some protection against the flu. You also can protect yourself against the flu by washing your hands frequently.

What's in a Flu Vaccine?

Flu vaccines are available as a shot or nasal mist (a type of spray that's squirted up the nose). The shot contains killed flu viruses that won't cause people to get the flu, but will cause the body to make antibodies to fight off infection by the live flu virus.

The flu shot is very effective at protecting against the flu, but it's not 100%. A few people who get the shot will get the flu. In addition, the shot only contains certain strains of the virus. If a new flu strain emerges, a person who's had a shot may not be protected against it.

If you hate getting shots, ask your doctor about the nasal mist vaccine. The nasal mist is different from the shot because it contains weakened live flu viruses instead of killed viruses. Because it contains live viruses, the nasal mist isn't for everyone. For example, people with weakened immune systems (from certain illnesses or medications) shouldn't get the nasal mist. Check with your doctor to see if you can get the nasal mist vaccine.

What About Side Effects?

It's possible to have some minor side effects for 1 or 2 days after getting a flu shot, like soreness in the area where you got the shot. Some people may feel achy or have a mild fever after getting the shot. But the side effects aren't as bad as the flu, which can make some people sick for as long as 2 or 3 weeks.

A few people who get the nasal mist vaccine can develop mild flu-like symptoms that go away after several days.

And if you have an egg allergy, get your flu shot in a doctor's office, not at a supermarket, drugstore, or other venue.

Reviewed by: Elana Pearl Ben-Joseph, MD
Date reviewed: January 2013