An influenza A epidemic caused by H1N1 virus.
D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000032:analysis; D003120:Colorado; D004196:Disease Outbreaks / Q000517:prevention & control; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D009980:Influenza A virus / Q000276:immunology / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000276:immunology
D000914:Antibodies, Viral