Which vaccine is recommended annually for all adults?

ANNUAL INFLUENZA VACCINATION: Recommended for: EVERYONE 6 months and older, annually; SPECIAL PRIORITY GROUPS (higher risk of severe flu): Adults 65+; Pregnant women; People with chronic conditions (heart disease, diabetes, asthma, kidney disease, immunocompromise); Healthcare workers (to protect themselves and patients). WHY ANNUAL: Influenza virus mutates rapidly; each year's vaccine is updated to match predicted circulating strains; immunity from prior year's vaccine declines; the vaccine is reformulated annually. TIMING: Ideally September-October before flu season peaks (usually December-February); but vaccine any time during flu season is better than none. CONTRAINDICATIONS: Previous severe allergic reaction to the vaccine or any of its components. Egg allergy: most people with egg allergy can receive most flu vaccines; consult an allergist for history of anaphylaxis to egg.