SEROTYPE IDENTIFICATION OF PNEUMOCOCCI: A KEY TO EFFECTIVE VACCINE PREVENTION AND INFECTION MONITORING

Pneumococcal infection (PI) remains a major cause of morbidity and mortality in young children and older adults. It occurs in invasive (meningitis, bacteremic pneumonia, sepsis) and non-invasive (otitis media, sinusitis) forms. The pathogen, Streptococcus pneumoniae, has over 90 serotypes, with a few responsible for most invasive cases before vaccination. Asymptomatic carriage, especially among children, is the main source of transmission. The polysaccharide capsule is the key virulence factor, highlighting the need for continuous surveillance and vaccination strategies to reduce disease burden. Objective. To assess the importance of pneumococcal serotype identification for developing effective vaccination strategies and monitoring infection, and to highlight unresolved public health issues, including vaccination adherence and the need for large-scale regional studies. Materials and Methods. Data on pneumococcal serotypes were analyzed from laboratories, registries, and databases (PubMed, Scopus, Google Scholar, Cyberleninka, e-Library), along with Kazakhstan’s national epidemiological data (2016–2024) and childhood vaccination statistics, focusing on geographic and temporal serotype trends. Results. The results demonstrated that the serotype landscape of pneumococcal infection is variable and regionally specific. In Kazakhstan, during the COVID-19 pandemic in 2020, a decline in PCV13 vaccination coverage was observed; however, in the post-pandemic period (2022), a significant increase in coverage was recorded: 98.2%, 96.6%, and 97.7% for the first, second, and third doses, respectively. Discussion. The pneumococcal serotype profile is dynamic and requires national monitoring to inform vaccination strategies. In Kazakhstan, serotypes 19, 3, 23, and 4 remain relevant due to their link with invasive disease and resistance. The rollout of higher-valent vaccines (PCV15, PCV20) expands protection but highlights the need for ongoing surveillance to address serotype replacement and sustain disease control. Conclusion. Vaccination efforts in Kazakhstan from 2016–2024 improved coverage and awareness, especially post-pandemic. However, challenges remain, including the need for regional serotype studies, stronger interdisciplinary collaboration, greater awareness among providers and the public, and a national monitoring system to track serotype changes and vaccine effectiveness.