[Immunological factors in the evolution of the epidemic process in meningococcal infection].

The results obtained in 1987 in the study of the immunostructure of the population of Yaroslavl with respect to meningococcal polysaccharides, groups, A, B, C, and lipopolysaccharide are presented in comparison with earlier results obtained in 1976. The regulating role of the immunological factor in the evolution of the epidemic process of meningococcal infection has been confirmed. The level of antibodies to meningococcal polysaccharides, groups A and B, has been found to reflect the intensity of the circulation of the infective agent among the population. The comparison of the results of investigations carried out in 1976 and 1987 has revealed the essential role of the lipopolysaccharide antigen in the formation of the postinfection immunity of the population to meningococcal infection, irrespective of the group of the infective agent.