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Children's Vaccines Health Center

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Inactivated Influenza Vaccine: What You Need to Know


6. What are the risks from inactivated influenza vaccine?

A vaccine, like any medicine, could possibly cause serious problems, such as severe allergic reactions. The risk of a vaccine causing serious harm, or death, is extremely small. Serious problems from influenza vaccine are very rare. The viruses in inactivated influenza vaccine have been killed, so you cannot get influenza from the vaccine.

Mild problems:

  • soreness, redness, or swelling where the shot was given
  • fever
  • aches

If these problems occur, they usually begin soon after the shot and last 1-2 days.

Severe problems:

  • Life-threatening allergic reactions from vaccines are very rare. If they do occur, it is usually within a few minutes to a few hours after the shot.
  • In 1976, a type of influenza (swine flu) vaccine was associated with Guillain-Barré Syndrome (GBS). Since then, flu vaccines have not been clearly linked to GBS. However, if there is a risk of GBS from current flu vaccines, it would be no more than 1 or 2 cases per million people vaccinated. This is much lower than the risk of severe influenza, which can be prevented by vaccination.

7. What if there is a severe reaction?

What should I look for?

  • Any unusual condition, such as a high fever or behavior changes. Signs of a serious allergic reaction can include difficulty breathing, hoarseness or wheezing, hives,paleness, weakness, a fast heart beat, or dizziness.

What should I do?

  • Call a doctor, or get the person to a doctor right away.
  • Tell your doctor what happened, the date and time it happened, and when the vaccination was given.
  • Ask your doctor, nurse, or health department to report the reaction by filing a Vaccine Adverse Event Reporting System (VAERS) form. Or you can file this report through the VAERS web site at, or by calling 1-800-822-7967. VAERS does not provide medical advice.

8. The National Vaccine Injury Compensation Program

In the event that you or your child has a serious reaction to a vaccine, a federal program has been created to help pay for the care of those who have been harmed.

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