SURVEY OF INFLUENZA ANTIBODIES IN NORMAL HUMAN SERA IN PEKING

The results of influenza antibody determination in adult sera inthree successive years (1953-1955) and in children’s sera of different agegroups below 10 years of age suggest that A’ influenza was the mostwidespread virus in Peking, type C infection was nearly as widespread,while type B infection was more limited than types A and C. Since thesera of children below 10 years of age did not contain antibody againstthe PR8 or Lee strain, it is suggested that these two virus strains are oflittle significance in the etiology of influenza in recent years. The pre-sent data show that the antigenic evolution of different types of in-fluenza virus in Peking is basically similar to that seen elsewhere in theworld. The bearing of this work on the epidemiology of and immuniza-tion against influenza is discussed.