[Immunological structure of the population vis-à-vis the meningococcus].

The immunological and epidemiological study of 3362 serum samples selectively taken from healthy persons in Yaroslavl showed the presence of highly pronounced inverse correlation between morbidity rate indices and level of antibodies, as well as direct correlation between the level of carriership and the level of antibodies, which indicated the specific character of this process. The analysis of serological data showed that all meningococcal antigenic fractions took part in the formation of the immunological structure of the population, but lipopolysaccharides and polysaccharides played the most active role in this process. The level of all immunoglobulin classes (especially IgA) in the sera of the persons selected for this study was also shown to depend on their age.