Peer-reviewed article
Serotype distribution of remaining invasive pneumococcal disease after extensive use of ten-valent and 13-valent pneumococcal conjugate vaccines (the PSERENADE project): a global surveillance analysis.
Garcia Quesada M, Peterson ME, Bennett JC, Hayford K, Zeger SL et al. ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study analysed invasive pneumococcal disease patterns across 54 surveillance sites in 41 countries after widespread use of two pneumococcal vaccines (PCV10 and PCV13). The research found that after 5+ years of vaccine use, vaccine-targeted serotypes caused only 10-52% of disease in children under 5 and 15-46% in older adults, depending on which vaccine was used. Serotype 3 and 19A emerged as leading causes of remaining disease. Higher-valency vaccines (with more serotypes) are expected to prevent additional cases of the remaining disease.
Key points
- At PCV10 sites, vaccine-type serotypes caused only 10% of IPD in children under 5 and 15.5% in adults aged 50+
- At PCV13 sites, vaccine-type serotypes caused 26.4% of IPD in children under 5 and 29.5% in adults aged 50+
- Serotype 3 caused approximately 9% of cases in children under 5 and 14% in older adults across both vaccine types
- Serotype 19A was the leading cause at PCV10 sites (30.6% in children under 5)
- Higher-valency vaccines (PCV15, PCV20, PCV21, PCV24, PCV25) would target 4-53% of remaining disease cases depending on the vaccine
Limitations
The analysis is predominantly based on high-income countries (67% of sites) and mature vaccine programs with high uptake, so findings may not represent low- and middle-income country contexts or newer vaccination programs. The study describes serotype distribution after vaccine introduction but does not evaluate vaccine effectiveness or clinical outcomes.
Abstract
Background Widespread use of pneumococcal conjugate vaccines (PCVs) has reduced vaccine-type invasive pneumococcal disease (IPD). We describe the serotype distribution of IPD after extensive use of ten-valent PCV (PCV10; Synflorix, GSK) and 13-valent PCV (PCV13; Prevenar 13, Pfizer) globally. Methods IPD data were obtained from surveillance sites participating in the WHO-commissioned Pneumococcal Serotype Replacement and Distribution Estimation (PSERENADE) project that exclusively used PCV10 or PCV13 (hereafter PCV10 and PCV13 sites, respectively) in their national immunisation programmes and had primary series uptake of at least 70%. Serotype distribution was estimated for IPD cases occurring 5 years or more after PCV10 or PCV13 introduction (ie, the mature period when the serotype distribution had stabilised) using multinomial Dirichlet regression, stratified by PCV product and age group (<5 years, 5-17 years, 18-49 years, and ≥50 years). Findings The analysis included cases occurring primarily between 2015 and 2018 from 42 PCV13 sites (63 362 cases) and 12 PCV10 sites (6806 cases) in 41 countries. Sites were mostly high income (36 [67%] of 54) and used three-dose or four-dose booster schedules (44 [81%]). At PCV10 sites, PCV10 serotypes caused 10·0% (95% CI 6·3-12·9) of IPD cases in children younger than 5 years and 15·5% (13·4-19·3) of cases in adults aged 50 years or older, while PCV13 serotypes caused 52·1% (49·2-65·4) and 45·6% (40·0-50·0), respectively. At PCV13 sites, PCV13 serotypes caused 26·4% (21·3-30·0) of IPD cases in children younger than 5 years and 29·5% (27·5-33·0) of cases in adults aged 50 years or older. The leading serotype at PCV10 sites was 19A in children younger than 5 years (30·6% [95% CI 18·2-43·1]) and adults aged 50 years or older (14·8% [11·9-17·8]). Serotype 3 was a top-ranked serotype, causing about 9% of cases in children younger than 5 years and 14% in adults aged 50 years or older at both PCV10 and PCV13 sites. Across all age and PCV10 or PCV13 strata, the proportion of IPD targeted by higher-valency PCVs beyond PCV13 was 4·1-9·7% for PCV15, 13·5-36·0% for PCV20, 29·9-53·8% for PCV21, 15·6-42·0% for PCV24, and 31·5-50·1% for PCV25. All top-ten ranked non-PCV13 serotypes are included in at least one higher-valency PCV. Interpretation The proportion of IPD due to serotypes included in PCVs in use was low in mature PCV10 and PCV13 settings. Serotype distribution differed between PCV10 and PCV13 sites and age groups. Higher-valency PCVs target most remaining IPD and are expected to extend impact. Funding Bill & Melinda Gates Foundation as part of the WHO Pneumococcal Vaccines Technical Coordination Project.