Different Types of Flu Vaccines

Overview

Influenza (flu) vaccines cause antibodies to develop in the body about two weeks after vaccination. These antibodies provide protection against influenza caused by the viruses represented in the flu vaccines. The seasonal flu vaccine protects against the influenza viruses that research suggests will be most common during the upcoming season. These include three different main groups of influenza Type A (A(H1N1) and A(H3N2) and B viruses.

Trivalent flu vaccine

Trivalent flu vaccines protect against three different main groups of influenza Type A and B viruses. For the 2025-26 influenza season, all flu vaccines available in the United States are trivalent.

Flu shot

Flu shots are vaccines given with a needle, usually in the arm for adults and older children or leg for a young child. Flu vaccines given with a needle include inactivated flu vaccines (which contain inactivated flu viruses) and recombinant flu vaccine (which contains antigens from influenza viruses). Most inactivated flu vaccines are approved for people 6 months and older and recombinant flu vaccine is approved for people 9 years and older.

Cell-culture based flu vaccine

Most flu vaccines contain flu viruses which have been grown in eggs. The cell culture-based flu vaccine (Flucelvax) is an inactivated flu vaccine that contains viruses that are grown in a mammal cell culture instead of in hens' eggs. This vaccine is approved for people 6 months and older.

High-dose flu vaccine

The high dose vaccine (Fluzone High-Dose) is an inactivated flu vaccine that contains four times the amount of antigen (the part of the vaccine that helps your body build up protection against influenza viruses) as a regular inactivated flu shot to help create a stronger immune response. It is approved for people 65 years and older.

Adjuvanted flu vaccine

Adjuvanted flu vaccine (Fluad) is an inactivated flu vaccine that contains an ingredient called an adjuvant to help create a stronger immune response. It is approved for people 65 years and older.

Recombinant flu vaccine

Recombinant flu vaccine (Flublok) does not contain viruses. Instead, it contains only the influenza virus antigen (the part of the vaccine that helps your body build up protection against flu viruses). This vaccine contains three times the amount of antigen as standard-dose inactivated flu vaccines. It is approved for people 9 years and older.

Nasal spray flu vaccine

Live Attenuated Influenza Vaccine [LAIV] (FluMist) is given as a nasal spray. This vaccine is made with attenuated (weakened) live influenza viruses and is approved for use in people aged 2 through 49 years. This vaccine is not recommended for pregnant women, immunocompromised people, or people with certain medical conditions.

Flu vaccination by jet injector

Flu shots are usually given with a needle. One flu vaccine (Afluria) is also approved to be given using a jet injector. Although Afluria is approved for people 6 months and older, it is only approved to be given with a jet injector for people who are 18 through 64 years old. People in this age group can get this vaccine either with a jet injector or with a needle. People under 18 years old and over 64 years old can get this vaccine only with a needle. To give Afluria with a jet injector it is necessary to use the multidose formulation of the vaccine, which contains the preservative thimerosal. However, ACIP recommends that all recipients receive seasonal influenza vaccines only in single-dose formulations that are free of thimerosal as a preservative.

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