National immunization for pandemic influenza.
D004196:Disease Outbreaks / Q000517:prevention & control*; D006801:Humans; D007114:Immunization; D009980:Influenza A virus; D007252:Influenza Vaccines / Q000627:therapeutic use*; D007251:Influenza, Human / Q000517:prevention & control*; D014481:United States
D007252:Influenza Vaccines