From the Centers for Disease Control. Influenza vaccination levels, 1989-1991.
D000328:Adult; D000368:Aged; D006293:Health Promotion; D006801:Humans; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000517:prevention & control*; D014481:United States; D014611:Vaccination / Q000706:statistics & numerical data
D007252:Influenza Vaccines