Rationale for swine flu mass immunizations in 1976.
D004196:Disease Outbreaks; D006801:Humans; D007114:Immunization / Q000009:adverse effects; D007252:Influenza Vaccines / Q000009:adverse effects; D007251:Influenza, Human / Q000517:prevention & control*; D014481:United States
D007252:Influenza Vaccines