Skip to main content

Key Facts About Flu Vaccine

Who needs a flu vaccine?

Everyone aged 6 months and older, with rare exception, is recommended to receive annual flu vaccine. Flu vaccination helps protect you from getting sick with the flu and prevents you from passing it on to those who could get very sick from the flu.

Is there anyone who should not get a flu vaccine?

Children less than 6 months of age are too young to receive flu vaccine, which is why it's especially important everyone who comes into contact with young infants receives flu vaccine themselves. Also, if someone has had a serious allergic reaction (e.g., anaphylaxis) to a previous dose of flu vaccine or to one of the vaccine components*, they should not receive flu vaccine. Ask your healthcare provider which flu vaccine is right for you and your child. 

*Note: CDC updated their recommendations for people with egg allergies for the 2023-2024 flu season. All persons ages ≥6 months with egg allergy should receive influenza vaccine. Any influenza vaccine (egg based or non-egg based) that is otherwise appropriate for the recipient’s age and health status can be used.

Should pregnant women get a flu vaccine?

Yes. Flu vaccine is safe and has been given to millions of pregnant women over many years. It is recommended to protect the pregnant woman who is at high risk for severe flu illness and it protects the baby for up to 6 months after birth.

Infants younger than 6 months cannot receive a flu vaccination so it is essential that pregnant women receive a flu vaccination at any time during their pregnancy to protect themselves and their baby.

Are any of the flu vaccines recommended over the others?

Yes. For the 2023-2024 flu season, CDC and its Advisory Committee on Immunizations Practices (ACIP) recommends annual flu vaccination with any licensed age-appropriate flu vaccine, including inactivated influenza vaccine (IIV), recombinant influenza vaccine (RIV4), or live-attenuated influenza vaccine (LAIV4), for everyone 6 months and older. There is no preference for any one vaccine over another for individuals aged 6 months through 64 years.

A preferential recommendation has been given for individuals aged 65 years and older for the 2023-2024 flu season. CDC and ACIP are recommending a preference for high-dose inactivated influenza vaccine quadrivalent (HD-IIV4), quadrivalent adjuvanted inactivated influenza vaccine (aIIV4), or quadrivalent recombinant influenza vaccine (RIV4) for those who are 65 years and older. The recommendation states that if none of these three vaccines is available at an opportunity for vaccine administration, then any other age-appropriate influenza vaccine should be used. 

Can I get the flu from the flu vaccine?

No, a flu vaccine cannot cause flu illness. Flu shots are made with either a killed (inactivated) flu virus and are therefore not infectious, or with proteins from a flu virus instead of a flu vaccine virus. Nasal spray flu vaccine is made with weakened (attenuated) live flu viruses, and also cannot cause flu illness.

Some people may get mild and short-lasting symptoms, such as a low-grade fever or muscle-aches, but this is a sign that your body is responding to the vaccine. It is not the flu.

Does my child need 2 doses of flu vaccine for the 2023-2024 flu season?

Children aged 6 months through 8 years of age are recommended to receive 2 doses of flu vaccine, separated by at least 4 weeks, for the 2023-2024 flu season if they have not previously received at least 2 doses of flu vaccine prior to this flu season.

Children who need 2 doses of influenza vaccine administered at least 4 weeks apart are recommended to receive the first dose as soon as possible after vaccine becomes available.

Do I really need a flu vaccine every year?

Yes. Everyone aged 6 months and older, without contraindications, is recommended to receive a year flu vaccine. A person’s immune protection from vaccination declines over time, so an annual vaccination is needed to get the best protection from flu.

Also, flu viruses are constantly changing, so the composition of the viruses in the vaccine are reviewed each year and updated based on which viruses are circulating and making people sick.

When should I be vaccinated?

You should get a flu vaccine before viruses begin spreading in your community because it takes about two weeks after vaccination for antibodies to develop in the body and provide protection against flu. CDC recommends that everyone should get a flu vaccine by the end of October.

However, if you have not received your vaccination before October, getting vaccinated later in the season is still beneficial, even into January or later.

Children who need two doses of flu vaccine (see above) to be fully protected should be vaccinated as soon as vaccine is available, because the two doses must be given at least four weeks apart.