[Determination of antibody specificity to a new influenza B virus variant by means of the immunoadsorption test].

Immunoadsorption test was used for determination of the strainspecificity of antibody to a new antigenic variant of influenza B virus (B/Hong Kong/5/72 and B/Yamagata/1/73) in human sera collected in April, 1973--March, 1974. The new strains were shown to be circulating in Moscow City only late in February and in March 1974. The experimental data show the immunoadsorption test to give more definite ideas not only on the qualitative differences between strains but also on the specificity of the immunologic response.