Seasonal influenza vaccines are designed to protect against the influenza viruses that are expected to be most common during the upcoming flu season. The World Health Organization (WHO) recommends that seasonal influenza vaccines be updated annually to ensure that they are effective against the most recent strains of influenza viruses.
The identification of the correct 2024-2025 seasonal influenza vaccine formulation is a complex process that involves multiple steps. First, the WHO reviews data on the influenza viruses that have been circulating in different parts of the world during the previous year. This data is used to identify the strains of influenza viruses that are most likely to cause illness during the upcoming flu season.
