Influenza Vaccine Information
It is recommended that everyone 6 months and older in the United States should get the influenza (flu) vaccine every season. An annual seasonal flu vaccine is the best way to help reduce the risk of getting the flu and any of its potentially serious complications.
Vaccination has been shown to have many benefits, including reducing the risk of flu illnesses, hospitalizations, and even the risk of flu-related death. While some people who get a flu vaccine may still get sick with influenza, flu vaccination has been shown in several studies to reduce the severity of illness.
How do Flu Vaccines Work? Flu vaccines cause antibodies to develop in the body about two weeks after vaccination. These antibodies protect against flu illness. Seasonal flu vaccines are designed to protect against the influenza viruses that research indicates will be most common during the upcoming season. All flu vaccines in the United States protect against four different flu viruses: an influenza A(H1N1) virus, an influenza A(H3N2) virus, and two influenza B viruses.
Do Flu Vaccines Work Right Away? No. It takes about two weeks after vaccination for antibodies to develop in the body and provide protection against influenza virus infection. That’s why it’s best to get vaccinated before influenza viruses start to spread in your community.
Vaccine Effectiveness. Influenza (flu) vaccine effectiveness (VE) can vary. The protection provided by a flu vaccine varies from season to season and depends in part on the age and health status of the person getting the vaccine and the similarity or “match” between the viruses in the vaccine and those in circulation.
During years when the flu vaccine match is good, it is possible to measure substantial benefits from flu vaccination in terms of preventing flu illness and complications. However, the benefits of flu vaccination will still vary, depending on the characteristics of the person being vaccinated (for example, their health and age), what flu viruses are circulating that season, and, potentially, which type of flu vaccine was used. More information is available at Vaccine Effectiveness – How well does the Flu Vaccine Work?
Flu Vaccine Options. For people younger than 65 years, CDC does not preferentially recommend any licensed, age-appropriate influenza (flu) vaccine over another during the 2022-2023 flu season. Options for this age group include inactivated influenza vaccine [IIV], recombinant influenza vaccine [RIV], or live attenuated influenza vaccine (LAIV), with no preference for any flu vaccine over another.
New for this season: For people 65 years and older, three flu vaccines are preferentially recommended over standard-dose, unadjuvanted flu vaccines. These are the Fluzone High-Dose Quadrivalent vaccine, Flublok Quadrivalent recombinant flu vaccine , and Fluad Quadrivalent adjuvanted flu vaccine. More information is available at Flu & People 65 Years and Older.