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The Flu Vaccine

Why Get the Flu Vaccine?

If you've ever had the flu, you know how bad it can make you feel. To help skip all that misery — as well as possible health problems from the flu — doctors recommend that all teens get the flu vaccine every year.

There are other good reasons too:

  • It's extra important for people with some medical conditions (like kidney disease, diabetes, HIV, heart problems, or asthma) to get a flu vaccine. They're more likely to have serious health problems (like pneumonia) if they get the flu.
  • Kids and teens who take aspirin regularly also need the flu vaccine. They're at risk for getting a serious condition called if they get the flu.
  • Getting vaccinated protects the people around you. Because there's less chance you'll get the flu and pass it on, you help protect people who might get very ill from the flu — like babies, people with serious medical conditions, and the elderly.

It's extra important to get a flu vaccine during the 2020–2021 flu season as the coronavirus pandemic continues:

  • Preventing the flu will help you avoid needing medical care when health care providers are so busy caring for people with COVID-19.
  • Health experts worry that people who get the flu and COVID-19 at the same time might have a more serious illness.
  • The flu and COVID-19 cause similar symptoms. If you can avoid the flu and its symptoms, you'll be less likely to need testing (for the flu or coronavirus) or to isolate at home.

When Should I Get Vaccinated?

Flu viruses usually cause the most illness during the colder months of the year. In the United States, flu season is from October to May.

The best time to get a flu vaccine is before flu season starts. Getting it as soon as it's available, usually around September, gives the body time to build immunity. Your mom or dad can find out about vaccine availability from your doctor's office, or you can ask your school nurse.

Even if you can't get vaccinated right away, getting it later is better than not getting it at all. It's still flu season in January or February — even then it's not too late for you to get the flu vaccine.

What Are the Possible Side Effects of the Flu Vaccine?

Flu vaccines come in two forms, a shot and a nasal spray:

  • The flu shot usually is injected into the upper arm or thigh, depending on a person's age. It contains killed flu virus. It can cause soreness, redness, or swelling at the injection site. Rarely, it might cause a low fever or body aches.
  • The nasal spray flu vaccine contains weakened live flu viruses. So it may cause mild flu-like symptoms, such as a runny nose, wheezing, sore throat, vomiting, or tiredness. Like the shot, it can sometimes cause a low fever or body aches.

Both vaccine types cause the body to make antibodies to fight off infection by the live flu virus, and they work equally well. This flu season (2020–2021), get whichever vaccine your doctor recommends. People with weak immune systems or some health conditions (such as asthma) and pregnant women should not get the nasal spray vaccine.

The flu vaccine is very good at protecting against the flu, but it's not 100%. And it only works against some types of the virus. If a new flu type appears, a person who's had the vaccine may not be protected against it.

A few people who get the vaccine might get the flu. But the illness will be much milder and go away sooner than if they weren't vaccinated.

What Else Should I Know?

  • If you have an egg allergy, get your flu shot in a doctor's office, not at a supermarket, drugstore, or other venue.
  • Sometimes people feel faint after getting a shot. To prevent this, you can sit or lie down for 15 minutes right after the shot.
Date reviewed: September 2020