The effectiveness of the flu vaccine for the 2024-2025 season generally ranges from about 30% to 60%, depending on the population and study. Vaccine effectiveness tends to be higher in children and adolescents (with up to 78% reduction in hospitalization risk) and lower in older adults, who may have a weaker immune response. In outpatient settings, it ranges roughly from 32-60%, while effectiveness against hospitalization can be 63-78% in children and adolescents. However, effectiveness can be lower in adults under 60 and can vary year by year based on how well the vaccine matches circulating virus strains. Despite some fluctuation, flu vaccination still provides meaningful protection, especially against severe outcomes like hospitalization and death.
Key Points on Flu Vaccine Effectiveness:
- For the 2024-2025 season, vaccine effectiveness in primary care was estimated at about 31% overall and 69% against hospitalization in Germany.
- Children and adolescents may see vaccine effectiveness up to 78% against hospitalization.
- Older adults have lower vaccine effectiveness but still gain important protection against severe illness.
- Flu vaccine effectiveness varies annually due to virus mutation and strain match.
- Repeated annual vaccination generally maintains consistent protection.
- Timing of vaccination (usually September-October) is crucial for optimal protection during peak flu season.
In summary, the flu vaccine is moderately effective in preventing influenza infection and is especially effective in preventing severe illness and hospitalizations in children and adults, supporting continued annual vaccination.
