What are the side effects of the seasonal live, attenuated nasal spray flu vaccine?

A vaccine, like any medicine, could possibly cause serious problems, such as severe allergic reactions. However, the risk of a vaccine causing serious harm, or death, is extremely small.

Live influenza vaccine viruses rarely spread from person to person. Even if they do, they are not likely to cause illness.

Live, attenuated nasal spray flu vaccine is made from weakened virus and does not cause influenza. The vaccine can cause mild symptoms in people who get it.

Mild problems:

Some children and adolescents 2-17 years of age have reported mild reactions, including:

• runny nose, nasal congestion or cough
• fever
• headache and muscle aches
• wheezing
• abdominal pain or occasional vomiting or diarrhea

Some adults 18-49 years of age have reported:

• runny nose or nasal congestion
• sore throat
• cough, chills, tiredness/weakness
• headache

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 vaccination.
   
• If rare reactions occur with any product, they may not be identified until thousands, or millions, of people have used it. Millions of doses of live, attenuated nasal spray flu vaccine have been distributed since it was licensed, and no serious problems have been identified. Like all vaccines, live, attenuated nasal spray flu vaccine will continue to be monitored for unusual or severe problems.

Last Reviewed: 10/18/2010

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