This season’s flu shot appears to be moderately effective, similar to a typical year, and offers meaningful protection especially against severe illness and hospitalization. Even in years when effectiveness is not perfect, vaccination still significantly lowers the risk of getting the flu, needing intensive care, or dying from influenza.
Current season effectiveness
For the 2024–2025 season in the U.S., interim data show overall vaccine effectiveness in about the 40–60% range at preventing lab-confirmed flu that leads to a doctor or emergency visit. Protection against hospitalization appears higher, with several networks estimating reductions in flu-related hospital admissions of roughly 40–70% depending on age group and setting.
What that means for you
A flu shot does not guarantee you will not get sick, but it substantially cuts your chances and makes illness milder if you do get infected. This is particularly important for older adults, young children, pregnant people, and those with chronic conditions, who have the highest risk of severe flu outcomes.
Age and risk differences
Effectiveness varies by age: children and younger adults often see higher protection than the very old, but older adults still gain clear benefit against hospitalization and death. High-dose or adjuvanted flu vaccines are recommended for many people 65 and older to boost immune response and improve protection.
Why experts still recommend it
Even a “50% effective” flu shot means your risk of medically attended flu is cut roughly in half and your risk of the worst outcomes drops even more. Public health agencies continue to recommend annual flu vaccination for everyone 6 months and older because of these reductions in serious illness, hospital use, and deaths.
