Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
The influenza vaccine is an immunization designed to protect against the influenza virus, commonly known as the flu. It stimulates the immune system to produce antibodies specific to the virus, reducing the risk of infection.
5 Must Know Facts For Your Next Test
Influenza vaccines are updated annually to match circulating strains due to the high mutation rate of the virus.
There are two main types of influenza vaccines: inactivated (killed) and live attenuated (weakened).
Influenza vaccines can be administered via injection or nasal spray.
The effectiveness of the influenza vaccine varies each year but typically ranges between 40-60%.
Vaccination is especially recommended for high-risk groups such as young children, elderly individuals, and those with chronic health conditions.