Persistent Dominance of Serotype 3 in Noninvasive Pneumococcal Disease in Belgium (2022-2025).

Noninvasive pneumococcal disease (NIPD) represents a substantial portion of the total pneumococcal disease burden worldwide. In this cross-sectional study, the serotype distribution for isolates originating from NIPD patients in Belgium (2022-2025) is described. Serotype 3 was the serotype with the largest NIPD burden in Belgium (n = 178, 12.7%), and detailed analyses revealed that its burden was lower in infants <2 years when compared to older age groups. Pneumococcal conjugate vaccines PCV20 and PCV21 cover approximately 50% to 80%, respectively, of circulating serotypes responsible for NIPD in Belgium, which underlines the importance of improving vaccine uptake in the adult population.