Influenza Vaccine Side Effects

Different side effects can be associated with the influenza shot and LAIV.

The influenza shot: The viruses in the influenza shot are killed (inactivated), so you cannot get the flu from a influenza shot. Some minor side effects:

• Aches
• Fever (low)
• Soreness
• Redness
• Local swelling where the shot was given

If these side effects occur, they begin soon after the shot and usually last 1 to 2 days. Almost all people who receive influenza vaccine have no serious problems from it. However, on rare occasions, flu vaccination can cause serious problems, such as severe allergic reactions.

LAIV (FluMist®): The viruses in the nasal-spray vaccine are weakened and do not cause severe symptoms often associated with influenza illness. (In clinical studies, transmission of vaccine viruses to close contacts has occurred only rarely.)

In adults, side effects from LAIV (FluMist®) can include

• sore throat
• runny nose
• cough
• headache

In children, side effects from LAIV (FluMist®) can include

• fever
• muscle aches
• vomiting
• headache
• wheezing
• runny nose