[The antigenic interrelationships between influenza A (H2) viruses determined by the mathematical processing of the data from immunoenzyme analysis using monoclonal antibodies to the M1 and NP proteins].

Antigenic relationships among 15 influenza A (H2) virus strains of human and avian origin were determined by ELISA titers with monoclonal antibodies (MCA) to Ml and NP proteins. Minor antigenic variations were found in Ml protein. One MCA to NP protein (469/6) showed different reactivity with human and avian influenza viruses. Analyses of antigenic relationships among influenza viruses were performed according to a computerized taxonomic cluster procedure. The evolutionary relatedness of these viruses is discussed.