The effect of a previous attack of A1 influenza on susceptibility to A2 virus during the 1957 outbreak.
D004196:Disease Outbreaks; D004198:Disease Susceptibility; D058872:Epidemics; D006801:Humans; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000276:immunology*; D009975:Orthomyxoviridae; D012621:Seasons; D014611:Vaccination
D007252:Influenza Vaccines
INFLUENZA/immunology