The first and most important step in protecting against the flu is to get a flu shot each year.
Because flu viruses change each season, flu vaccines are updated yearly based on worldwide surveillance to protect against the three or four viruses that the research suggests will be most common. This year, the vaccine includes an influenza A (H1N1) virus, an influenza A (H3N2) virus, and one or two influenza B viruses, depending on the vaccine.
Who should get the seasonal flu vaccine?
Everyone 6 months of age and older should be vaccinated against influenza every year. Different flu shots are approved for people of different ages. Everyone should get a vaccine that is appropriate for their age.
- There are standard-dose inactivated influenza vaccines that are approved for people as young as 6 months of age. Some vaccines are only approved for adults. For example, the recombinant influenza vaccine is approved for people aged 18 years and older, and the adjuvanted and high-dose inactivated vaccines are approved for people 65 years and older.
- Pregnant people and people with certain chronic health conditions can get a flu shot.
- People with egg allergy can get a flu shot
- Find out more from the Centers for Disease Control and Prevention (CDC)
Who should not receive a flu vaccination?
There are some people who should not be vaccinated for flu. These include:
- Children younger than 6 months of age are too young to get a flu shot.
- People with severe, life-threatening allergies to any ingredient in a flu vaccine (other than egg proteins) should not get that vaccine. This might include gelatin, antibiotics, or other ingredients. See Special Considerations Regarding Egg Allergy for more information about egg allergies and flu vaccine.
- People who have had a severe allergic reaction to a dose of influenza vaccine should not get that flu vaccine again and might not be able to receive other influenza vaccines. If you have had a severe allergic reaction to an influenza vaccine in the past, it is important to talk with your health care provider to help determine whether vaccination is appropriate for you.
People who should talk to their health care provider before getting a flu shot:
If you have one of the following conditions, talk with your health care provider. He or she can help decide whether vaccination is right for you, and select the best vaccine for your situation:
- If you have an allergy to eggs or any of the ingredients in the vaccine. Talk to your doctor about your allergy. See Special Considerations Regarding Egg Allergy for more information about egg allergies and flu vaccine.
- If you ever had Guillain-Barré Syndrome (a severe paralyzing illness, also called GBS). Some people with a history of GBS should not get a flu vaccine. Talk to your doctor about your GBS history.
- If you had a severe allergic reaction to a previous dose of any other flu vaccine, talk to your health care provider.
- If you are not feeling well, talk to your doctor about your symptoms.
Please talk to your health care provider if you have concerns about receiving the flu vaccine.
When should I get vaccinated against seasonal flu?
Yearly flu vaccination should begin soon after flu vaccine is available, and ideally by October. However, getting vaccinated even later can be protective, as long as flu viruses are circulating. While seasonal influenza outbreaks can happen as early as October, most of the time influenza activity peaks in January or later.
Since it takes about two weeks after vaccination for antibodies to develop in the body that protect against influenza virus infection, it is best that people get vaccinated so they are protected before influenza begins spreading in their community. Find out more from the Centers for Disease Control and Prevention (CDC) Key Facts about Influenza.
Types of Flu Vaccines
There are two types of flu vaccines:
- “Flu shots” — inactivated vaccines (containing killed virus) that are given with a needle. The flu shots being produced for the United States market now are:
- The regular seasonal flu shot is “intramuscular” which means it is injected into muscle (usually in the upper arm). It has been used for decades and is approved for use in people 6 months of age and older, including healthy people, people with chronic medical conditions and pregnant women. Regular flu shots make up the bulk of the vaccine supply produced for the United States. Flu shots protect you against three or four strains of flu.
- A high-dose vaccine for people 65 and older which also is intramuscular. This vaccine was first made available during the 2010-2011 season. Fluzone High-Dose Seasonal Influenza Vaccine Q&A
- An intradermal vaccine for people 18 to 64 years of age which is injected with a needle into the “dermis” or skin. This vaccine was made available for the first time during the 2011-2012 season.
- A recombinant influenza vaccine that does not include any chicken egg protein. This influenza vaccine should be used for persons with severe allergic reactions to eggs. This vaccine has been available since the 2013-2014 season.
- The nasal-spray flu vaccine — a vaccine made with live, weakened flu viruses that is given as a nasal spray (sometimes called LAIV for “Live Attenuated Influenza Vaccine”). The viruses in the nasal spray vaccine do not cause the flu. LAIV is approved for use in healthy* people 2 to 49 years of age who are not pregnant.
Children and Vaccination
The Centers for Disease Control and Provention (CDC) recommends that all children 6 months and older get a seasonal flu vaccine.
Children 6 months through 8 years who are getting vaccinated for the first time, and some who have been vaccinated previously, will need two doses. Talk to your child’s health care provider to learn more about the flu vaccine for your child. More information can be found at the CDC website Children, the Flu, and the Flu Vaccine.
Getting a flu vaccine is safe
Flu vaccines have a very good safety history. Millions of flu vaccines have been given safely over the many decades that flu vaccines have been recommended. The flu vaccine provides protection that lasts through the flu season. A flu vaccine reduces your risk of illness, hospitalization, or even death and can prevent you spreading the virus to your loved ones.
The Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) hold vaccines to the highest safety standards. More information on vaccine safety and adverse events can be found on the CDC website.
The flu shot cannot cause flu illness. Learn more about this and other misconceptions at the Centers for Disease Control and Prevention (CDC) website Misconceptions about Seasonal Flu and Flu Vaccines.