Each year, there are more than 20,000 influenza associated deaths during influenza virus epidemics. There is an increase in hospital admission for patients with pneumonia, exacerbation of chronic obstructive pulmonary disease, croup, and congestive heart failure, and an increase in school and industrial absenteeism. Yet only 30% of the high-risk target population receives influenza vaccination annually. Health care providers and patients are reluctant to use vaccine despite its generally excellent record of safety and its approximately 70% efficacy when vaccine and epidemic strains match. The continuing change in antigenic composition of the influenza A virus and waning immunity requires annual vaccination. Vaccine composition and target groups are reviewed. Strategies for improving vaccine usage are emphasized.