[Immune bacteriolysis reaction in the assessment of immunological effectiveness of serogroup B meningococcal vaccine].

The immunological efficacy of serogroup B meningococcal protein-polysaccharide vaccine was studied in newly developed immune bacteriolysis test. Serogroup B meningococcus strains had different sensitivities to the bactericidal effects of immune sera. A single injection of the vaccine caused an induction of bactericidal antibodies to meningococcus vaccinal strain. Three weeks after vaccination 77.7% of the vaccines developed an appreciable increase of the titers of bactericidal antibodies to the homologous strain of meningococcus. The concentration of bactericidal antibodies to strain 2394 differing from the homologous strain by its serotype did not increase. In the controls no changes in the titers of bactericidal antibodies to both strains of meningococcus were observed, the level of antibodies being the same as that before vaccination in the group of subjects immunized with B vaccine; this proves the specificity of the immunizing effect to serogroup B meningococcus vaccinal strain (No 125).