How often should the influenza vaccine be administered to adults?

The influenza vaccine should be administered annually to adults because the composition of the vaccine is updated each year to match the circulating strains of the virus. Influenza viruses mutate frequently, leading to new variants that may not be effectively combated by the vaccine from the previous year. Annual vaccination ensures that individuals are protected against the most current strains and helps to maximize immunity in the population, reducing the risk of widespread outbreaks. This practice is critical not only for individual health but also for community health by maintaining herd immunity and preventing the spread of influenza during the peak season.