Influenza, or the "flu", is a serious disease that spreads from infected persons during the flu season each year (peaks from December to March).  Influenza causes fever, sore throat, cough, headache, chills, and muscle aches.

Who Should Receive the Vaccine and When?

Children who have a chronic illness, such as kidney disease, heart disease or asthma, should receive the flu shot.  Also, anyone 6 months to 18 years of age on long-term aspirin treatment should receive the vaccine because Reye's Syndrome can develop if they catch influenza.  

Because influenza activity can start as early as December, the best time to get the vaccine is during October and November.  But getting the vaccine after November can still provide protection against the flu.

• People 9 years and older need one shot.
• Children less than 9 years old need two shots, given one month apart, the first time they are vaccinate.

Who Should Not Be Vaccinated?

There are some people who should not be vaccinated without first consulting a physician. These include the following:

• People who have a severe allergy to chicken eggs.
• People who have had a severe reaction to an influenza vaccination in the past.
• People who developed Guillain-Barr Syndrome (GBS) within 6 weeks of getting an influenza vaccine previously.
• Influenza vaccine is not approved for use in children less than 6 months of age.
• People who have a moderate or severe illness with a fever should wait to get vaccinated until their symptoms lessen.

What are the Risks from the Influenza vaccine?

Like other medicines, a vaccine is capable of causing serious problems, such as severe allergic reactions.  The risk of influenza vaccine causing serious harm, or death, is extremely small.  The vaccine will not cause influenza.

Mild Problems:

• Soreness, redness, or swelling where the shot was given
• Fever
• Aches

Centers for Disease Control and Prevention