What to know
Influenza viruses change from year to year, so influenza vaccines must be updated annually to include the viruses that will most likely circulate in the upcoming season. Once the viruses are selected for the new formulation, private manufacturers produce, test, release and distribute influenza vaccine.
Vaccine Information
Influenza viruses change from year to year, so influenza vaccines must be updated annually to include the viruses that will most likely circulate in the upcoming season. Once the viruses are selected for the new formulation, private manufacturers produce, test, release and distribute influenza vaccine.
Flu vaccine is produced by private manufacturers, so supply depends on manufacturers. Vaccine manufacturers have projected that they will supply the United States with 148 million doses of influenza vaccines for the 2024-2025 season. These projections may change as the season progresses. All flu vaccines for the 2024-2025 season will be trivalent (three component). Most will be thimerosal-free, and most will be egg-based.