Peer-reviewed article
Persistence of vaccine-induced serotype-related pathology in invasive pneumococcal disease in children. Community of Madrid, 2007-2024.
Jesús Íñigo-Martínez, Juan Carlos Sanz-Moreno, Fernando Martín-Martínez, Macarena Garrido-Estepa, Ana María Humanes-Navarro et al. ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study examines trends in invasive pneumococcal disease (IPD) in children aged 0-17 years in Madrid from 2007 to 2024, following the introduction of pneumococcal conjugate vaccines. Despite high vaccination coverage, IPD cases increased, with rates for vaccine-covered serotypes rising between 2.3 and 7.0 times by 2024. Some vaccine-targeted serotypes like ST1, ST5, and ST7F disappeared, while others like ST14 and ST24A emerged or increased significantly. The findings suggest that vaccination has altered the landscape of pneumococcal disease by shifting the serotype composition rather than eliminating IPD.
Key points
- 1,856 IPD cases were notified between 2007-2024, with 53.6% occurring in children aged 1-4 years
- Incidence rates for serotypes covered by PCV7, PCV13, PCV15, and PCV20 increased 7.0, 2.9, 2.3, and 1.5 times respectively by 2024
- Serotypes 24A, 14, 15A, 10A, and 3 showed the largest increases, with ST14 increasing 17.8-fold
- Serotypes 1, 5, and 7F were eliminated (not detected in 2024), and ST19A declined to 2.2%
- The increase in IPD occurred despite very high vaccination coverage since 2007
Limitations
The study is a surveillance analysis describing trends in notified cases and cannot establish causation or assess vaccination effectiveness directly. It does not provide information about vaccination coverage rates, vaccine-prevented cases, or clinical outcomes of IPD in vaccinated versus unvaccinated children.
Abstract
INTRODUCTION: Pneumococcal conjugate vaccines (PCVs) were implemented in the childhood vaccination program of the Community of Madrid (CM) in 2007, but despite very high vaccination coverage since then, increasing trends in invasive pneumococcal disease (IPD) have been observed in recent years. METHODS: Epidemiological, clinical, and microbiological data from the Notifiable Disease Surveillance System on IPD cases in children aged 0-17 years in the CM during the period 2007-2024 were analysed. A descriptive analysis was conducted by sex, age-group, clinical presentation, laboratory results, prior vaccination, and antibiotic resistance. Incidence rates (IRs) and IR ratios (IRRs) were calculated overall and by serotypes (STs) covered by each vaccine and the most relevant STs using 2015-2019 as reference period. RESULTS: Between 2007 and 2024, 1,856 cases of IPD were notified: 1,052 (56.7%) in boys and 804 (43.3%) in girls. By age-group, there were 431 cases (23.2%) in < 1 year, 994 (53.6%) in those aged 1-4 years, and 431 (23.2%) in those aged 5-17 years. PCV7, PCV13, PCV15, and PCV20 vaccine included STs IRs increased 7.0, 2.9, 2.3, and 1.5 times, respectively (all P < 0.05), in 2024. STs 24A, 14, 15A, 10A, and 3 IRs also increased (IRRs: 30.5, 17.8, 2.8, 2.7, and 2.6, respectively; all P < 0.05). No strains of the STs 1, 5, or 7F were detected in 2024, and STs 19A decreased to 2.2%. CONCLUSIONS: IRs for children and adolescents increased between 2022 and 2024 in the CM, associated to the rise of some PCVs STs, as ST14, while the still persistent ST3 started to decline after 2022.
Findings the Hub has extracted
Each claim below is labelled by its type of design and links back to this report.
- Intervention
- Pneumococcal conjugate vaccine programme (PCV7 from 2007, with subsequent introduction of PCV13, PCV15, and PCV20)
- Population
- Children aged 0-17 years in the Community of Madrid with invasive pneumococcal disease
Key finding
Incidence rates for PCV7-covered serotypes increased 7.0-fold by 2024 despite vaccination since 2007
Íñigo-Martínez et al. · PubMed (US National Library of Medicine) · 3 Feb 2026