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Flu Shot (Influenza Vaccine)

What is the flu?

The flu (influenza) is a disease caused by viruses. Each winter many people get the flu. Influenza causes a fever, muscle aches, sore throat, cough, and tiredness that may last for several days. The disease can usually be prevented by getting a vaccine, commonly called a flu shot.

Who should get a flu shot?

Healthy children age 6 months to 5 years should routinely get a flu shot. Those less than 2 years old are at a greater risk of needing to be put in the hospital because of the flu.

A flu shot is also recommended each year for children ages 6 months and older if they have certain medical risk factors. These risk factors include:

  • Asthma or other lung disease
  • Congenital heart disease with defects that require medications or surgery or other heart disease
  • Glomerulonephritis, kidney failure, or other kidney disease
  • Diabetes or other metabolic disease
  • Sickle cell disease or other anemia
  • Immune system problems caused by a disease or medicine
  • Juvenile rheumatoid arthritis or any other disease needing aspirin therapy.

Other people who should have a flu shot include:

  • People over 50 years of age or older
  • Women who will be in the fourth to ninth month(s) of pregnancy during the influenza season
  • Residents of nursing homes or chronic care facilities.

If you have an otherwise healthy child and want your child to avoid getting the flu, your child may get a flu shot.

Are there other ways to get the vaccine?

An alternative to flu shots is FluMist. It is a nasal spray form of the vaccine for children over 5 years of age. It costs more than the shot. As with flu shots, your child will need a new dose of FluMist every year. Unlike the shot, FluMist is a live virus vaccine. For this reason pregnant women and children with weakened immune systems, asthma, or certain other medical conditions cannot take the nasal spray.

When are flu shots given?

A flu shot can be given at the same time as any routine vaccine. Your child should get the shot between September and mid-November, if possible. Protection from the influenza virus usually lasts only for 1 year.

For more information about the vaccine, ask your health care provider for an Influenza Vaccine Information Statement. If your child has an allergy to eggs or a history of Guillain-Barre syndrome, talk to your provider about these problems before getting the flu shot.

Are there any other considerations?

Mild symptoms after a flu shot include soreness at the site of the shot, fever, and body aches. These problems usually last for one or two days. Serious complications are very rare. Ask your health care provider for a Vaccine Information Statement from the Centers for Disease Control for more information.

A flu shot contains a very small amount of a preservative called thimerosal. This is an ethyl mercury-based compound. Research has shown that the amount of mercury in an influenza shot is not harmful.

Written by Robert Brayden, MD, Associate Professor of Pediatrics, University of Colorado School of Medicine.
Published by McKesson Provider Technologies.
Last modified: 2006-09-12
Last reviewed: 2006-08-22
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright 2006 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.
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