[Immunological effectiveness of a dried group-A meningococcal polysaccharide vaccine].

The immunological effectiveness of dried group A meningococcal polysaccharide vaccine, developed at the Gabrichevsky Research Institute of Epidemiology and Microbiology, Moscow, for children aged 5-14 years was studied. The intensiveness of the immune response of children to 0.5 ml of the vaccine introduced in a single injection was evaluated by a rise in the level of agglutinating antibodies to group A meningococcal polysaccharide in the sera of the vaccinees 3-4 weeks after immunization with the following optimum doses: 25 micrograms for children aged 5-8 years, 50 micrograms for children aged 9-13 years and 75 micrograms for children aged 14 years and over. The vaccine was shown to be highly immunogenic. Antibodies to group A meningococcal polysaccharide were identified as IgM. These antibodies in a titer of 1:40 and higher could be detected in 90% of the vaccinated children in the younger age group, 7 months after immunization.