[Optimal inoculation doses of meningococcal chemical polyvalent ABC-vaccine for immunizing children of different ages. II. A study of the immunological effectiveness of different doses of the preparation].

The study of meningococcal chemical polyvalent ABC-vaccine, manufactured by the Mechnikov Research Institute for Vaccines and Sera (Moscow), was carried out with the aim of finding the optimum vaccination doses for the immunization of children aged 0.5-15 years. In this study the effectiveness of the vaccine was evaluated by the determination of the titers of specific bactericidal antibodies in paired serum samples obtained before and 30 days after immunization. The analysis of the frequency of positive seroconversions and the levels of the geometric mean antibody titers allowed the authors to reveal the presence of a distinct relationship between the intensity of antibody production and the dose of the vaccine under test, used for immunization, as well as to establish that pronounced immune response to the optimum dose developed in 95-100% of the vaccinees. Taking into account the results obtained in the earlier studies of the safety and reactogenicity of the preparation (see Communication I), the optimum vaccination doses for the immunization of children of different age groups were established. On the basis of the statistical analysis of the characteristics of immune response to different doses of the preparation the following doses were chosen as optimum: 80 micrograms for children aged 0.5-2 years, 100 micrograms for children aged 3-7 years, 120 micrograms for children aged 8-11 years, 160 micrograms for children aged 12-15 years.