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Influenza immunization (vaccine)

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Illustrations

Influenza vaccines
Influenza vaccines
Influenza
Influenza

Alternative names    Return to top

Vaccine - influenza; Flu shot immunization; Flu vaccine

Definition    Return to top

This vaccination protects people from contracting influenza, a viral illness affecting the respiratory tract.

Information    Return to top

In the U.S., "flu" outbreaks typically occur in winter months. Symptoms of influenza include fever, chills, muscle aches, and cough. Although the illness usually only lasts 3 to 7 days, some people have more severe cases or complications that require hospitalization.

Thousands of people in the U.S. die each year as the result of the flu or its complications. Most of those who die are the elderly, young children, or people with compromised immune systems.

The viruses that cause influenza change rapidly. Influenza vaccines are developed each year to protect people from the strains expected to be most prevalent. All the viruses in the vaccine are killed, so it is not possible to get the flu from the vaccine. However, some people do experience a low-grade fever afterwards as their immune systems gear up to recognize the virus.

Flu vaccination is generally given at the beginning of the "flu season" -- usually late October or early November in the United States. People traveling to other countries should be aware that influenza may occur at different times of the year in other areas.

IMMUNIZATION SCHEDULE

The vaccine is recommended for high-risk people 6 months and older as well as those in contact with them (including household contacts):

The vaccine is also recommended for health care providers attending to high-risk people:

The influenza vaccine is encouraged for:

Children under age 9 require two shots one month apart the first time that they receive influenza vaccine. Other people require a single shot each year.

BENEFITS

Most people achieve protection from influenza vaccine approximately 2 weeks after receiving the immunization.

Immunization of high-risk people decreases many potential deaths from influenza. Immunization of those caring for high-risk people decreases the potential of spreading the "flu" from otherwise healthy people to those who are at higher risk of complications.

RISKS

Most people have no side effects from the influenza vaccine. Soreness at the injection site or minor aches and low grade fever may be present for several days.

Unlike the swine flu vaccine used in1976, flu vaccines in recent years have shown no association with Guillain-Barre syndrome (GBS) in children, and an extremely small increase in the risk of GBS in adults (approximately 1 more case per million persons immunized). This risk is far outweighed by the amount of severe influenza prevented by immunization.

As is the case with any drug or vaccine, there is a remote possibility that allergic reactions, more serious reactions, or even death may occur after receiving the flu shot.

DELAY OR DO NOT GIVE

Influenza vaccine should be withheld or only given to the following after consultation with the primary care provider:

POST-IMMUNIZATION SYMPTOMS AND CARE

Watch for and be familiar with how to treat minor side effects, such as injection site tenderness or low grade fever.

CALL THE PRIMARY HEALTH CARE PROVIDER IF:

Update Date: 11/10/2003

Updated by: A.D.A.M. editorial. Previously reviewed by Adam Ratner, M.D., Children's Hospital of Philadelphia, Philadelphia, PA. Review provided by VeriMed Healthcare Network.

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The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2002 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.