Influenza surveillance 1998/99.
D000368:Aged; D006801:Humans; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D011159:Population Surveillance; D006113:United Kingdom / Q000453:epidemiology
D007252:Influenza Vaccines