Influence of vaccine prevention on the spread and serotype composition of Streptococcus pneumoniae in military collectives

Objective. Study of the effect of vaccination against pneumococcal infection on the prevalence and serotype composition of S. pneumoniae in military personnel.Materials and methods. The study was conducted among 369 military personnel of the military unit of the Sverdlovsk region. Determination of the frequency and serotype of S. pneumoniae was carried out upon admission and after 1.5 months of stay in the military collective using the multiplex PCR method.Results. After 1.5 months of stay of servicemen in the military collective, a significant activation of pneumococcal circulation was established (χ2McNemar=24.038; p0.001). The risk of S. pneumoniae infection among unvaccinated military personnel was 1.39 times higher compared to vaccinated military personnel (RR=1.39; 95% CI 1.209–1.596). In the group of unvaccinated military personnel, the frequency of occurrence of vaccine serotypes was 2.6 times higher than in vaccinated ones (χ2 = 6.25; p = 0.01).Conclusions. The proactive influence of immunization against pneumococcal infection on the prevalence and serotype landscape of S. pneumoniae has been established: A low prevalence of vaccine serotypes and a predominance of non-typeable serotypes have been revealed among vaccinated individuals.