Influenza Vaccine, Inactivated (patient information)

Why get vaccinated?

Influenza (flu) is a contagious disease. It is caused by the influenza virus, which spreads from person to person through coughing or sneezing. Other illnesses have the same symptoms and are often mistaken for influenza. But only the influenza virus can cause influenza.

Anyone can get influenza. For most people, it lasts only a few days. It can cause: fever, sore throat, chills, fatigue, cough, headache, and muscle aches.

Some people get much sicker. Influenza can lead to pneumonia and can be dangerous for people with heart or breathing conditions. It can cause high fever and seizures in children. Influenza kills about 36,000 people each year in the United States, mostly among the elderly.

Influenza vaccine can prevent influenza.

Inactivated Influenza vaccine

There are two types of influenza vaccine:

• An inactivated (killed) vaccine, or flu shot, has been used in the United States for many years. It is given by injection.
• A live, weakened vaccine was licensed in 2003. It is sprayed into the nostrils. This vaccine is described in a separate monograph.

Influenza viruses are always changing. Therefore, influenza vaccines are updated every year, and an annual vaccination is recommended. For most people influenza vaccine prevents serious influenza-related illness. It will not prevent influenza-like illnesses caused by other viruses.

It takes about 2 weeks for protection to develop after the vaccination, and protection can last up to a year.

Inactivated influenza vaccine may be given at the same time as other vaccines, including pneumococcal vaccine.

Some inactivated influenza vaccine contains thimerosal, a preservative that contains mercury. Some people believe thimerosal may be related to developmental problems in children. In 2004 the Institute of Medicine published a report concluding that, based on scientific studies, there is no evidence of such a relationship. If you are concerned about thimerosal, ask your doctor about thimerosal-free influenza vaccine.

Who should get inactivated influenza vaccine?

Inactivated influenza vaccine can be given to people 6 months of age and older. It is recommended for people who are at risk of complications from influenza, and for people who can spread influenza to those at high risk (including all household members).

People at high risk for complications from influenza:

• People 65 years of age and older.
• Residents of long-term care facilities housing persons with chronic medical conditions.
• People who have long-term health problems with: heart disease; kidney disease; lung disease; metabolic disease, such as diabetes; asthma; anemia, and other blood disorders.
• People with certain muscle or nerve disorders (such as seizure disorders or severe cerebral palsy) that can lead to breathing or swallowing problems.
• People with a weakened immune system due to: HIV/AIDS or other diseases affecting the immune system, long-term treatment with drugs such as steroids, cancer treatment with x-rays or drugs
• People 6 months to 18 years of age on long-term aspirin treatment (these people could develop Reye Syndrome if they got influenza).
• Women who will be pregnant during influenza season.
• All children 6-59 months of age.

People who can spread influenza to those at high risk:

• Household contacts and out-of-home caretakers of children from 0-59 months of age.
• Physicians, nurses, family members, or anyone else in close contact with people at risk of serious influenza.

Influenza vaccine is also recommended for adults 50-64 years of age and anyone else who wants to reduce their chance of getting influenza.

A yearly influenza vaccination should be considered for:

• People who provide essential community services.
• People living in dormitories or under other crowded conditions, to prevent outbreaks.
• People at high risk of influenza complications who travel to the Southern hemisphere between *April and September, or to the tropics or in organized tourist groups at any time.

When should I get influenza vaccine?

The best time to get influenza vaccine is in October or November.

Influenza season usually peaks in February, but it can peak any time from November through May. So getting the vaccine in December, or even later, can be beneficial in most years.

Some people should get their flu shot in October or earlier:

• people 50 years of age and older,
• younger people at high risk from influenza and its complications (including children 6 through 59 months of age),
• household contacts of people at high risk,
• health care workers, and
• children younger than 9 years of age getting influenza vaccine for the first time.

Most people need one flu shot each year. Children younger than 9 years of age getting influenza vaccine for the first time should get 2 doses, given at least one month apart.

Who should talk with a doctor before getting influenza vaccine?

Some people should not get inactivated influenza vaccine or should wait before getting it.

• Tell your doctor if you have any severe (life-threatening) allergies. Allergic reactions to influenza vaccine are rare. Influenza vaccine virus is grown in eggs. People with a severe egg allergy should not get the vaccine. A severe allergy to any vaccine component is also a reason to not get the vaccine. If you have had a severe reaction after a previous dose of influenza vaccine, tell your doctor.
• Tell your doctor if you ever had Guillain-Barré Syndrome (a severe paralytic illness, also called GBS). You may be able to get the vaccine, but your doctor should help you make the decision.
• People who are moderately or severely ill should usually wait until they recover before getting flu vaccine. If you are ill, talk to your doctor or nurse about whether to reschedule the vaccination. People with a mild illness can usually get the vaccine.

What are the risks from inactivated influenza vaccine?

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

Serious problems from influenza vaccine are very rare.The viruses in inactivated influenza vaccine have been killed, so you cannot get influenza from the vaccine.

Mild Problems

• soreness, redness, or swelling where the shot was given
• fever
• aches
• If these problems occur, they usually begin soon after the shot and last 1-2 days.

Severe Problems:

• Life-threatening allergic reactions from vaccines are very rare. If they do occur, it is within a few minutes to a few hours after the shot.
• In 1976, a certain type of influenza (swine flu) vaccine was associated with Guillain-Barré Syndrome (GBS). Since then, flu vaccines have not been clearly linked to GBS. However, if there is a risk of GBS from current flu vaccines, it would be no more than 1 or 2 cases per million people vaccinated. This is much lower than the risk of severe influenza, which can be prevented by vaccination.

What if there is a severe reaction?

What should I look for?

Any unusual condition, such as a high fever or behavior changes. Signs of a serious allergic reaction can include difficulty breathing, hoarseness or wheezing, hives, paleness, weakness, a fast heart beat or dizziness.

What should I do?

• Call a doctor, or get the person to a doctor right away.
• Tell your doctor what happened, the date and time it happened, and when the vaccination was given.
• Ask your health care provider to file a Vaccine Adverse Event Reporting System (VAERS) form if you have any reaction to the vaccine. Or call VAERS yourself at 1-800-822-7967, or visit their website at http://vaers.hhs.gov.

The National Vaccine Injury Compensation Program

In the rare event that you or your child has a serious reaction to a vaccine, a federal program has been created to help pay for the care of those who have been harmed.

For details about the National Vaccine Injury Compensation Program, call 1-800-338-2382 or visit the program's website at http://www.hrsa.gov/vaccinecompensation.

How can I learn more?

Ask your doctor or other health care provider. They can give you the vaccine package insert or suggest other sources of information. Call your local or state health department's immunization program. Contact the Centers for Disease Control and Prevention (CDC): call 1-800-232-4636 (1-800-CDC-INFO) or visit the National Immunization Program's website at http://www.cdc.gov/nip.

Inactivated Influenza Vaccine Information Statement. U.S. Department of Health and Human Services/Centers for Disease Control and Prevention National Immunization Program. 6/30/2006.

Brand names

• Fluarix®
• FluLaval®
• Fluvirin®
• Fluzone®