| Abstract: | Radioimmunoassay were carried out with influenza A/Cambridge/46, A/FM/1/47, A/England/1/51, A/Denwer/1/57, and A/USSR/90/79 of the H1N1 subtype to determine the antigenic determinants of influenza A/USSR/90/77 virus hemagglutinin. The test system included 125I-labeled hemagglutinin of A/USSR/90/77 virus and homologous antiserum to this virus. The most marked antigenic similarity was found between A/USSR/90/77 and A/USSR/90/79 viruses. The A/Cambridge/46 and A/Denwer/1/57 viruses showed clear-cut differences in the antigenic determinants from the A/USSR/90/77 virus. |
