Circulating serotypes of Streptococcus pneumoniae in unvaccinated children: epidemiological analysis and pharmacoeconomic justification of vaccination in the Republic of Belarus

Purpose. Pneumococcal infections, caused by the diversity of Streptococcus pneumoniae serotypes, remain a significant concern in pediatric practice. Since the effectiveness of vaccine prophylaxis directly depends on the match between vaccine serotypes and circulating strains, the aim of this study is to comprehensively assess the serotype structure of S. pneumoniae in unvaccinated children, their associated clinical manifestations, and to provide a pharmacoeconomic rationale for a vaccination strategy for the pediatric population of Belarus.

Materials and methods. Serotyping was performed on 297 clinical S. pneumoniae isolates obtained from unvaccinated children in Minsk (2020–2023). The pharmacoeconomic analysis of the vaccination effectiveness for infants in their first year of life (with 95 % coverage) was conducted using a Markov model and a cost-benefit analysis approach for the healthcare system of Belarus. Pneumococcal conjugate vaccines (PCV) PCV-10 and PCV-13 were compared assuming an identical cost per full vaccination course (3 doses).

Results. Serotypes 19F, 3, 19A, 14, and 23F predominated, constituting 73,9 % of all S. pneumoniae isolates. Non-typeable strains (8,4 %) were strongly associated with acute purulent otitis media (80,0 %; p < 0.001). Multiple serotype isolation (5,7 % of patients) was predominantly observed in bilateral otitis media (81,3 %); serotype 19F dominated in these cases (75,0 %). PCV-13 demonstrated a significantly higher coverage of circulating strains (85,5 %) compared to PCV-10 (62,9 %; p < 0.05), and was comparable to PCV-20 (90,9 %; p > 0.05). Pharmacoeconomic modeling confirmed the advantage of PCV-13: maximum reduction in pneumonia incidence (68,0 % vs 22,0 %, respectively; p < 0,001) and otitis media incidence (78,0 % vs 67,1 %, respectively; p < 0,001), along with twofold superiority in budget savings (26,6 % vs 13,0 %, respectively). Based on high serotype coverage and proven clinical-economic effectiveness, PCV-13 represents the optimal choice for inclusion in the National Immunization Schedule of Belarus.

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