The swine antigen in previous influenza vaccines.
D000328:Adult; D000956:Antigens, Viral / Q000008:administration & dosage*; D006801:Humans; D009980:Influenza A virus / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000517:prevention & control; D008887:Military Medicine; D009975:Orthomyxoviridae / Q000276:immunology*; D014481:United States
D000956:Antigens, Viral; D007252:Influenza Vaccines