2024-2025 Flu Season
Getting an annual flu vaccine is the first and best way to protect yourself and your family from the flu. Flu vaccination can reduce flu illnesses, leading to fewer doctors’ visits, and missed work and school due to flu, as well as prevent flu-related hospitalizations. The more people who get vaccinated, the more people will be protected from flu, including older people, very young children, pregnant women, and people with certain health conditions who are more vulnerable to serious flu complications. The following section summarizes information about the 2024-2025 flu season.
What’s new with flu vaccinations for 2024-2025?
A few things are different for the 2024-2025 influenza (flu) season, including:
- The composition of flu vaccines has been updated.
- Influenza B viruses are classified into two lineages: B/Yamagata and B/Victoria. However, the evidence indicates that the B/Yamagata lineage virus no longer poses a public health threat. During the October 2023 meeting, the committee unanimously voted to recommend excluding the B/Yamagata lineage component from quadrivalent seasonal influenza vaccines as soon as possible.
In the interest of public health, the FDA strongly recommended to influenza vaccine manufacturers the removal of the B/Yamagata lineage virus from seasonal influenza vaccines in the U.S. for the 2024-2025 influenza season. FDA and the manufacturers have been working together so that the move from quadrivalent to trivalent seasonal influenza vaccines occurs for the upcoming influenza season. - The recommended timing of vaccination is similar to last season. For most people who need only one dose for the season, September and October are generally good times to get vaccinated. Vaccination in July and August is not recommended for most adults but can be considered for some groups. While ideally, it’s recommended to get vaccinated by the end of October, it’s important to know that vaccination after October can still provide protection during the peak of flu season.
What viruses will the 2024-2025 flu vaccines protect against?
There are many different flu viruses, and they are constantly changing. The composition of U.S. flu vaccines is reviewed annually and updated as needed. Trivalent seasonal influenza vaccines for 2024-2025 include two influenza A viruses (H1N1 and H3N2) and one influenza B virus.
The recommendations for egg-based, and cell-based, and recombinant flu vaccines are listed below:
Egg-based vaccine composition recommendations for 2024-2025:
- an A/Victoria/4897/2022 (H1N1)pdm09-like virus;
- an A/Thailand/8/2022 (H3N2)-like virus; and
- a B/Austria/1359417/2021 (B/Victoria lineage)-like virus.
Cell- or recombinant-based vaccine composition recommendations for 2024-2025:
- an A/Wisconsin/67/2022 (H1N1)pdm09-like virus;
- an A/Massachusetts/18/2022 (H3N2)-like virus; and
- a B/Austria/1359417/2021 (B/Victoria lineage)-like virus.
For more information, visit the FDA website.
