Flu Shot Questions and Answers

Have questions about the flu vaccine? Find answers here.

Why is it important to get a flu shot?+

The seasonal flu is a serious disease and people of any age can get it. Infection can result in mild to severe illness and life-threatening complications. In an average year, the seasonal flu causes 36,000 deaths and 226,000 hospitalizations in the United States.

When is the best time to be vaccinated?+

The best time to get vaccinated is from October through November. Flu activity generally peaks between late December and March.

Does the flu vaccine work right away?+

No. It takes about two weeks after vaccination for the antibodies to develop in the body and provide protection against the flu virus. In the meantime, you are still at risk for getting the flu. So it's best to get vaccinated early in the fall, before flu season really gets under way.

Can I get the flu even if I had the flu vaccine?+

Yes. If you do get the flu after having the flu vaccine, it will likely be a far milder case than you otherwise would have had. The ability of flu vaccine to protect a person depends on:

  • The age and health status of the person getting vaccinated
  • The "match" between the virus strains in the vaccine and those in circulation
Why do I need to get vaccinated every year?+

Flu viruses change from year to year, which means:

  • You can get the flu more than once in a lifetime. The immunity that is built up from having the flu caused by one virus strain doesn't always protect against a new strain.
  • A vaccine made against flu viruses last year may not protect against the new viruses this year. The vaccine is updated to include current viruses every year.
Are there risks from getting a flu vaccine?+

There are risks associated with all vaccines. In very rare cases a vaccine, like any medicine, may cause serious problems, such as severe allergic reactions. The risk of the flu vaccine causing serious harm or death is extremely small. Almost all who get the vaccine have no serious problems.

Will I get the flu from the flu vaccine?+

No. The shot is made from killed or 'dead' viruses so you cannot get the flu from it. The nasal mist vaccine contains weakened live versions of the virus, designed to help protect the body from getting the flu without causing flu-like illness.

What side effects can occur from the flu vaccine?+

The most common side effects of the flu shot are soreness, redness or swelling at the injection site, and low fever. If these occur, they begin soon after the shot and usually last one to two days. Side effects of the nasal mist vaccine are generally mild and temporary. Runny nose is the most common. Others include various cold-like symptoms such as headache, cough, sore throat, tiredness/ weakness, irritability, and muscle aches.

Can I get the flu shot if I am pregnant or may be pregnant?+

Yes. In fact, not only are flu shots are considered safe for pregnant women, they’re actually recommended since you can pass immunity on to your unborn baby that will protect them in the first months of life. But pregnant women should not receive the nasal mist vaccine.