title: Update: influenza activity--United States--and influenza type B virus drift.
mesh_terms: D000914:Antibodies, Viral / Q000032:analysis; D004196:Disease Outbreaks / Q000453:epidemiology; D006801:Humans; D009981:Influenza B virus / Q000276:immunology; D007251:Influenza, Human / Q000453:epidemiology* / Q000382:microbiology; D014481:United States
chemical_list: D000914:Antibodies, Viral