New Antigenic Variant in Far East Influenza Epidemic,1957

Abstract

Summary

Viruses responsible for the widespread epidemic of influenza in the Far East during the spring of 1957 were caused by a type A virus which represented a major shift, antigenically, from the type A, A prime and swine influenza viruses of previous years. These conclusions are based on findings in tests of Far East and prototype A viruses with chicken and ferret antisera against Far East and prototype strains and in tests with paired sera from patients in the Far East and previous epidemics. The marked antigenic shift in Far East viruses, the deficiency of antibody against them in the human population tested, the rapid spread of the disease in the Far East, and the relatively high attack rates, all indicate the potential importance of the new viruses as a health problem in the U.S.A. and probably much of the world. During the present period, the new viruses are being called Far East influenza virus. 1957.∗