Complicated Pneumonia in Fully PCV13-Vaccinated Children: Persistent Morbidity in the Post-Vaccine Era – A Cohort Study From Eastern Europe

Abstract Aim To evaluate the clinical characteristics, microbiological aetiology, management strategies, and short-term outcomes of severe complicated community-acquired pneumonia (CAP) in fully PCV13-vaccinated children treated at a tertiary referral centre in Eastern Europe. Methods We conducted a retrospective cohort study of 25 previously healthy children hospitalised with severe complicated CAP between January 2023 and June 2024 in Eastern Slovakia. Demographic data, laboratory findings, microbiological results, therapeutic interventions, and outcomes were analysed. Management strategies (conservative treatment, intrapleural fibrinolysis, and surgery) were compared using non-parametric statistical methods. Results All children had completed PCV13 immunisation. A causative pathogen was identified in 92% of cases. Streptococcus pneumoniae remained the predominant pathogen (42%), followed by Staphylococcus aureus (24%) and Streptococcus pyogenes (12%). All patients developed pleural effusion requiring chest drainage; 56% received intrapleural fibrinolysis and 48% required surgical intervention. The median duration of chest drainage was 9 days, and the median length of hospitalisation was 24 days. No deaths occurred. Conclusion Severe complicated CAP persists despite complete PCV13 vaccination and remains associated with substantial morbidity and frequent invasive management. These findings highlight the need for strengthened microbiological surveillance, including pneumococcal serotyping, and optimisation of therapeutic strategies in the post-vaccine era.