Peer-reviewed article
Pneumococcal vaccines: A dose of change. Vaccine failures and breakthrough infections in Belgian children during the PCV13 era (2019-2024).
Cato Dambre, Laura Cornelissen, Lize Cuypers, Stefanie Desmet ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study examined vaccine failures and breakthrough infections in Belgian children aged 0-5 years who received pneumococcal conjugate vaccines (PCV13 or PCV10) between 2019 and 2024. Among 451 vaccinated children with invasive pneumococcal disease, 5.8% experienced vaccine failures and 8.2% had breakthrough infections, mostly caused by serotypes 19A and 3. The findings establish a baseline for comparing the effectiveness of newer, higher-valent pneumococcal vaccines being introduced in Belgium.
Key points
- Among 451 vaccinated children with invasive pneumococcal disease, 26 vaccine failures (5.8%) and 37 breakthrough infections (8.2%) were identified
- Vaccine failures were predominantly caused by serotypes 19A (61.5%), 3 (26.9%), and 14 (11.5%)
- Vaccine failures were associated with older age and invasive pneumonia, while breakthrough infections occurred more often in younger children
- No significant differences in breakthrough proportions remained between PCV10 and PCV13 after adjustment for serotype differences
- Study provides a national baseline for evaluating the real-world impact of higher-valent pneumococcal vaccines like PCV20
Limitations
This is a retrospective observational study based on surveillance data, which cannot establish causal relationships or control for all confounding variables affecting vaccine effectiveness. The study does not evaluate the effectiveness of newer vaccines like PCV20, only provides baseline data for future comparisons.
Abstract
BACKGROUND: Since 2019, PCV13 has replaced PCV10 in Belgium's childhood vaccination program, reducing IPD cases caused by PCV13 serotypes, mainly 19A, but accompanied by serotype replacement. This changing epidemiology prompted consideration of the higher-valent PCV20 vaccine. Despite broader serotype coverage, clinical effectiveness against certain serotypes remains uncertain, raising concerns about vaccine failures. To date, vaccine failures and breakthrough infections have not been systematically studied in Belgium. This study aims to establish a baseline by characterizing vaccine failures and breakthrough infections in children 0-5 years old during the recent PCV13 era, providing a reference point ahead of PCV20 introduction. METHODS: We conducted a retrospective cohort study including children ≤5 years diagnosed with IPD in Belgium from 2019 to 2024, using surveillance data from the National Reference Centre for invasive pneumococci and the PediSurv network. Vaccine failures and breakthrough infections were identified and characterized by serotype and clinical characteristics. RESULTS: Of 543 pediatric IPD cases with known vaccination status, 451 (83 %) had received at least one dose of pneumococcal conjugate vaccine. Among these, we identified 26 vaccine failures (5.8 %) and 37 breakthrough infections (8.2 %). Differences in breakthrough proportions between PCV10 and PCV13 were primarily driven by PCV13-exclusive serotypes, after adjustment no significant differences remained. Vaccine failures were caused by serotypes 19A (61.5 %), 3 (26.9 %), and 14 (11.5 %), and were associated with older age (OR: 1.49; 95 % CI: 1.18-1.89) and invasive pneumonia (OR: 3.89; 95 % CI: 1.66-9.12). Breakthrough infections involved serotypes 19A (70.3 %), 3 (13.5 %), 14 (13.5 %), and 19F (2.7 %) and occurred more often in younger children (OR: 0.61; 95 % CI: 0.42-0.87). CONCLUSION: These findings provide the first national baseline of vaccine failures, offering a reference point for evaluating PCV20 introduction. Continued monitoring will be essential to assess the real-world impact of higher-valent pneumococcal vaccines and to guide evidence-based vaccination policy.
Findings the Hub has extracted
Each claim below is labelled by its type of design and links back to this report.
- Intervention
- Pneumococcal conjugate vaccination (PCV10 or PCV13) as part of Belgium's childhood vaccination program
- Population
- Children aged 0-5 years in Belgium diagnosed with invasive pneumococcal disease (IPD) from 2019-2024
Key finding
5.8% of vaccinated children with IPD experienced vaccine failures (26 of 451 cases)
Dambre et al. · PubMed (US National Library of Medicine) · 5 Dec 2025