[Epidemiology of influenza].
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D008875:Middle Aged; D009975:Orthomyxoviridae
D007252:Influenza Vaccines