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Flu Shot: The Vaccine and Its Side Effects

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    What are some of the side effects?

    You might have a mild fever and feel tired or achy after you get vaccinated. Some people also have soreness, redness, or swelling where they got their shot. These problems aren’t serious and don’t last long.

    Serious side effects are very rare. If they do happen, it's within a few minutes to a few hours after getting the shot. Call your doctor right away if you have trouble breathing, hives, feel weak or dizzy, or have a fast heartbeat after you get a flu shot.

    Who can get the vaccine as a nasal spray?

    FluMist is only for healthy people ages 2 to 49. The CDC says healthy children 2 through 8 years old can get the nasal spray vaccine when it is available. But if it’s not, kids should go ahead and get the traditional flu shot rather than wait to vaccinate.

    Because the nasal spray vaccine contains weakened strains of live virus, the following people shouldn’t take it:

    • Pregnant women
    • Children under age 5 who have wheezing that comes and goes
    • Children and teens who take aspirin
    • People with a medical condition that puts them at high risk for complications from the flu, including those with long-lasting heart or lung disease (such as asthma), diabetes, kidney disease, or a weakened immune system

    What are the side effects of the nasal spray vaccine (FluMist)?

    Side effects in children can include:

    • Runny nose
    • Headache
    • Vomiting
    • Muscle aches
    • Fever

    Side effects in adults can include:

    • Runny nose
    • Headache
    • Sore throat

    WebMD Medical Reference

    Reviewed by Roy Benaroch, MD on April 23, 2015
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