Influenza ("flu") is a contagious disease that spreads around the United States every winter, usually between October and May.
Flu is caused by the influenza virus, and can be spread by coughing, sneezing and close contact.
Anyone can get the flu, but the risk of getting flu is highest among children.
Symptoms can occur suddenly and may last several days. They can include:
- sore throat
- muscle aches
- runny or stuffy nose
Flu can make some people much sicker than others.
These people include young children, people 65 and older, pregnant women and people with certain health conditions – such as heart, lung or kidney disease, or a weakened immune system. Flu vaccine is especially important for these people, and anyone in close contact with them.
Flu can also lead to pneumonia and make existing medical conditions worse. It can cause diarrhea and seizures in children.
Each year thousands of people in the United States die from flu, and many more are hospitalized.
Flu vaccine is the best protection people have from flu and its complications.
Flu vaccine also helps prevent spreading flu from person-to-person.
There are two types of influenza vaccine:
The flu vaccine, which does not contain any live influenza virus. As a result, you can’t get the flu from getting a flu shot, which dispels a belief by some that you can get the flu from getting a flu shot.
A different, live, attenuated (weakened) influenza vaccine is sprayed into the nostrils.
Flu vaccine is recommended every year. Children 6 months through 8-years of age should get two doses the first year they are vaccinated.
Each year’s flu vaccine is made to protect from viruses that are most likely to cause disease that year.
While flu vaccine cannot prevent all cases of flu, it is the best defense against the disease. Inactivated flu vaccine protects against 3 or 4 different influenza viruses.
It takes about two weeks for protection to develop after the vaccination and protection lasts several months to a year. That dispels another belief by some that if you get a flu shot early in the flu season, that it won’t last throughout the entire season.
You can experience mild problems after getting a flu shot, which include:
- soreness, redness or swelling where the shot was given
- hoarseness; sore, red or itchy eyes; cough
If these problems occur, they usually begin soon after the shot and last 1 or 2 days.
Some people could experience a severe allergic reaction after getting a flu shot (estimated less than 1 in a million doses).
For more information on the safety of flu vaccines, visit: www.cdc.gov/vaccinesafety/.
If you have a severe reaction to a flu shot, it should be reported to the Vaccine Adverse Event Reporting System (VAERS).
Your doctor might file that report, or you can do it yourself through the VAERS Website at www.vaers.hhs.gov or by calling toll-free, 1-800-822-7967. VAERS is only for reporting reactions. They do not give medical advice.
People who believe they may have been injured by a vaccine can learn about the National Vaccine Injury Compensation Program (VICP) and how to file a claim by calling toll-free, 1-800-338-2382 or visiting the VICP Website at www.hrsa.gov/vaccinecompensation.
For more information about the flu and how to protect yourself from it, ask your doctor, call your local or state health department or contact the CDC at 1-800-232-4636 or online at www.cdc.gov/flu.