Effectiveness of trivalent and quadrivalent influenza vaccines in preventing infection, hospitalization, and severe outcomes in the 2023-2024 season onwards

Vaccination is considered the best method to prevent serious outcomes associated with influenza infection. Influenza viruses constantly evolve, requiring continuous global monitoring and frequent reformulation of vaccines. Given this, the effectiveness of influenza vaccines can vary from season to season, depending on factors such as the match between vaccine strains and circulating viruses, as well as the age and health status of vaccinated individuals. Monitoring vaccine performance is crucial for understanding and improving vaccination benefits.