[Analysis of heterogenous populations of antihemagglutinating antibodies in hyperimmune sera against influenza virus by indirect solid-phase radioimmunoassay].

Populations of antihemagglutinating antibodies in hyperimmune rabbit sera to influenza A/PR8/34, A/Moscow/PAN/52, and A/Swine Iowa/15/31 viruses were examined by indirect competitive solid phase radioimmunoassay (SPRIA). Under conditions of competitive assay with immobilized virus homologous to the serum under test, not all subpopulations of cross-reacting antibodies in the sera are identified. Competition in the system of immobilized heterologous virus identifies a fuller spectrum of cross-reacting antibody. A composite analysis of the sera under both variants of competition showed each of the sera to contain a heterogenous population of antibodies interacting to various extents with determinants of a number of heterologous viruses classified, according to 1971 Nomenclature, as viruses with H0, H1, and Hsw1 hemagglutinin subtypes. The identification of cross-reacting antibodies permitted a conclusion on the existence of both antigenic determinants on the surface of hemagglutinin molecules of the viruses under study and an analysis of their variability. The pattern of changes of similar determinants in transition from viruses of one subtype to viruses of another subtype is characteristic of the drift type.