Safety and reactogenicity of a group-A meningoccal polysaccharide vaccine for children 5 to 14

The safety and reactogenicity of group A meningococcal polysaccharide vaccine prepared at the G. N. Gabrichevsky Research Institute for Epidemiology and Microbiology (Moscow) and intended for the immunization of children aged 5-14 years were studied. The data obtained in this study made it possible to characterize the preparation as safe and mildly reactogenic. Shifts in the blood formula registered 24 hours after the injection of the vaccine remained within the limits of physiological fluctuations. Subfebrile temperature persisting for 2 days was registered in some of the children aged 5-8 years. Local reaction in the form of hyperemia at the site of injection was insignificant. The optimum vaccination dose will be determined on the basis of the whole complex of the data presented in this work, as well as the data on the immunological activity of the preparation.     

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.