Influenza vaccine can prevent influenza (flu).
Flu is a contagious disease that spreads around the United States every year, usually between October and May. Anyone can get the flu, but it is more dangerous for some people. Infants and young children, people 65 years of age and older, pregnant people, and people with certain health conditions or a weakened immune system are at greatest risk of flu complications.
Pneumonia, bronchitis, sinus infections, and ear infections are examples of flu-related complications. If you have a medical condition, such as heart disease, cancer, or diabetes, flu can make it worse.
Flu can cause fever and chills, sore throat, muscle aches, fatigue, cough, headache, and runny or stuffy nose. Some people may have vomiting and diarrhea, though this is more common in children than adults.
In an average year, thousands of people in the United States die from flu, and many more are hospitalized. Flu vaccine prevents millions of illnesses and flu-related visits to the doctor each year.
CDC recommends everyone 6 months and older get vaccinated every flu season. Children 6 months through 8 years of age may need 2 doses during a single flu season. Everyone else needs only 1 dose each flu season.
Live, attenuated influenza vaccine (called "LAIV") is a nasal spray vaccine that may be given to non-pregnant people 2 through 49 years of age.
It takes about 2 weeks for protection to develop after vaccination.
There are many flu viruses, and they are always changing. Each year a new flu vaccine is made to protect against the influenza viruses believed to be likely to cause disease in the upcoming flu season. Even when the vaccine doesn't exactly match these viruses, it may still provide some protection.
Influenza vaccine does not cause flu.
Influenza vaccine may be given at the same time as other vaccines.
Tell your vaccination provider if the person getting the vaccine:
- Is younger than 2 years or older than 49 years of age
- Is pregnant. Live, attenuated influenza vaccine is not recommended for pregnant people
- Has had an allergic reaction after a previous dose of influenza vaccine, or has any severe, life-threatening allergies
- Is a child or adolescent 2 through 17 years of age who is receiving aspirin or aspirin- or salicylate-containing products
- Has a weakened immune system
- Is a child 2 through 4 years old who has asthma or a history of wheezing in the past 12 months
- Is 5 years or older and has asthma
- Has taken influenza antiviral medication in the last 3 weeks
- Cares for severely immunocompromised people who require a protected environment
- Has other underlying medical conditions that can put people at higher risk of serious flu complications (such as lung disease, heart disease, kidney disease like diabetes, kidney or liver disorders, neurologic or neuromuscular or metabolic disorders)
- Does not have a spleen, or has a non-functioning spleen
- Has a cochlear implant
- Has a cerebrospinal fluid leak (a leak of the fluid that surrounds the brain to the nose, throat, ear, or some other location in the head)
- Has had Guillain-Barré Syndrome within 6 weeks after a previous dose of influenza vaccine
In some cases, your health care provider may decide to postpone influenza vaccination until a future visit.
For some patients, a different type of influenza vaccine (inactivated or recombinant influenza vaccine) might be more appropriate than live, attenuated influenza vaccine.
People with minor illnesses, such as a cold, may be vaccinated. People who are moderately or severely ill should usually wait until they recover before getting influenza vaccine.
Your health care provider can give you more information.
- Runny nose or nasal congestion, wheezing, and headache can happen after LAIV vaccination.
- Vomiting, muscle aches, fever, sore throat, and cough are other possible side effects.
If these problems occur, they usually begin soon after vaccination and are mild and short-lived.
As with any medicine, there is a very remote chance of a vaccine causing a severe allergic reaction, other serious injury, or death.
An allergic reaction could occur after the vaccinated person leaves the clinic. If you see signs of a severe allergic reaction (hives, swelling of the face and throat, difficulty breathing, a fast heartbeat, dizziness, or weakness), call 9-1-1 and get the person to the nearest hospital.
For other signs that concern you, call your health care provider.
Adverse reactions should be reported to the Vaccine Adverse Event Reporting System (VAERS). Your health care provider will usually file this report, or you can do it yourself. Visit the VAERS website at www.vaers.hhs.gov or call 1-800-822-7967. VAERS is only for reporting reactions, and VAERS staff members do not give medical advice.
The National Vaccine Injury Compensation Program (VICP) is a federal program that was created to compensate people who may have been injured by certain vaccines. Claims regarding alleged injury or death due to vaccination have a time limit for filing, which may be as short as two years. Visit the VICP website at www.hrsa.gov/vaccinecompensation or call 1-800-338-2382 to learn about the program and about filing a claim.
- Ask your health care provider.
- Call your local or state health department.
- Visit the website of the Food and Drug Administration (FDA) for vaccine package inserts and additional information at www.fda.gov/vaccines-blood-biologics/vaccines.
- Contact the Centers for Disease Control and Prevention (CDC):
- Call 1-800-232-4636 (1-800-CDC-INFO) or
- Visit CDC's website at www.cdc.gov/flu.
Vaccine Information Statement
Live, Attenuated Influenza Vaccine
42 U.S.C. § 300aa-26
Department of Health and Human Services
Centers for Disease Control and Prevention
Many vaccine information statements are available in Spanish and other languages. See www.immunize.org/vis.
Hojas de información sobre vacunas están disponibles en español y en muchos otros idiomas. Visite www.immunize.org/vis.