The flu vaccine effectiveness for the 2024-2025 flu season ranged broadly depending on the population and virus subtype but generally showed moderate effectiveness. Overall vaccine effectiveness estimates from multiple studies and networks in the U.S. indicate effectiveness around 42% to 56% in outpatient settings for all ages, with children often showing higher protection (up to about 60%) and adults ranging from about 36% to 55%. Protection against hospitalization tended to be higher, with estimates of 63% to 78% effectiveness especially in children and adolescents. Effectiveness can vary by influenza type, with generally higher efficacy against influenza A(H1N1)pdm09 and lower but still significant protection against A(H3N2) strains. The data also highlight that enhanced vaccines for older adults (65+) such as adjuvanted or high-dose vaccines offer better protection than standard-dose vaccines. In summary, the flu vaccine is moderately effective in preventing influenza illness each season, reducing risks of outpatient illness by roughly 40-60% and providing stronger protection against severe outcomes like hospitalization. Effectiveness varies by age group, virus subtype, and vaccine formulation, but it remains a crucial tool in flu prevention. This aligns with CDC vaccine effectiveness estimates and studies from recent flu seasons including 2024-2025, and enhances understanding of how the vaccine performs in real-world settings across different populations.