[Immunogenicity of the antigenic determinants of influenza virus type B hemagglutinin]

The immunogenic activity of antigenic determinants of influenza type B viruses in primary and booster immunizations was studied. In primary immunization, the highest immunogenicity was found with the type- and strain-specific antigenic determinants whereas the antigenic determinants of group specificity were less immunogenic. After booster immunizations the animal sera had antibody to all 3 antigenic determinants.