Evaluation of the immunological activity and safety of group B meningococcal vaccine prepared from a natural complex of specific polysaccharide and outer membrane proteins

: Immunological activity and safety of group B meningococcal vaccine prepared from a natural complex of specific polysaccharide and outer membrane proteins were under study. The immunological safety of the vaccine was evaluated by the absence of antibodies to denaturated and native DNA (d-DNA and n-DNA). As shown with the use of the enzyme immunoassay (EIA), the administration of the vaccine did not induce antibody formation to d-DNA and n-DNA during the observation period. The titer of bactericidal antibodies in the immune bacteriolysis assay (IBA) to the vaccine strain B:2b:P1.2 after immunization increased four-fold and greater in 80% of the vaccinated persons. The significant increase of bactericidal antibodies to heterologous strains B:2a:P1.2 and B:15:P1.7 was registered in 20-30% of the vaccinees, respectively. A month after the repeated vaccination an increase in specific IgG antibodies to the complex antigen was found to occur according to EIA results. The use of RIB made it possible to evaluate the preventive activity of group B meningococcal vaccine as a whole and to suppose that the vaccine induced mainly type-specific response.