[Functional activity of monoclonal and monospecific antibodies in the interaction with antigenic sites of influenza virus hemagglutinin].

Monospecific antibodies to three nonoverlapping sites of influenza A/Singapore/1/57 (H2N2) virus isolated from hyperimmune serum by specific adsorption were characterized by capacity to inhibit virus hemagglutination, immunochemically interact with hemagglutinin, and neutralize the virus (6-7.5 lg). Monoclonal antibodies to the same virus hemagglutinin displayed an even higher activity than monospecific antibodies in serological and immunochemical tests and were characterized by a rather low (1.0-4.5 lg) or null activity in biological neutralization of the virus.