Influenza immunisation.
D006801:Humans; D009980:Influenza A virus; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000517:prevention & control*; D006113:United Kingdom / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D014611:Vaccination
D007252:Influenza Vaccines