[Production of recombinants antigenically identical to influenza virus strains circulating in nature]

Recombination of a human influenza virus with an avian influenza virus produced a H2Nav2 recombinant with the antigenic properties analogous to those of avian influenza virus (H2Nav2) isolated from wild ducks in the Far East, USSR. Recombination of two avian influenza viruses yielded a recombinant H2N2, an antigenic analogues of influenza A/Singapore/1/57 (H2N2) virus which had started an epidemic of influenza in 1957.