| Title: |
The impact of pneumococcal conjugate vaccines on disease epidemiology, serotype distribution, and antimicrobial resistance in children. A 25-year observational study in Athens, Greece (1996–2021) |
| Authors: |
Vasiliki P. Syriopoulou; George L. Daikos; Emmanouil I. Koutouzis; Elizabeth-Barbara Tatsi; Theano Georgakopoulou; Foteini I. Koutouzi; Ageliki Stathi; Kalliopi Spyridopoulou; Anthi Sideri; Anastasios Doudoulakakis; Georgios Kalogeras; Theodota Liakopoulou; Dimitra-Maria Koukou; Chara Asimaki; Eleni Tsapra; Evangelia Lebessi; Levantia Zachariadou; Eleni Papadogeorgaki; Athanasios Michos |
| Source: |
Human Vaccines & Immunotherapeutics, Vol 22, Iss 1 (2026) |
| Publisher Information: |
Taylor & Francis Group |
| Publication Year: |
2026 |
| Collection: |
Directory of Open Access Journals: DOAJ Articles |
| Subject Terms: |
Streptococcus pneumoniae; pneumococcal disease; serotypes; vaccines; antimicrobial susceptibility; multidrug resistance; Immunologic diseases. Allergy; RC581-607; Therapeutics. Pharmacology; RM1-950 |
| Description: |
Streptococcus pneumoniae continues to cause invasive pneumococcal disease (IPD) and non-IPD in children, despite widely implemented pneumococcal conjugate vaccines (PCVs). This study evaluated the impact of PCV7 and PCV13 on pneumococcal disease (PD), serotype distribution, and antimicrobial resistance in children ≤14 years in Athens, Greece. We conducted a retrospective multicenter study in five pediatric hospitals covering ~80% of Athens’ pediatric population in three time periods; pre-PCV (1996–2005), post-PCV7 (2006–2010), and post-PCV13 (2011–2021). Clinical, microbiological, and demographic data were collected for children with PD. Capsular typing was performed by the Quellung reaction. Untypeable or antiserum cross-reacting isolates were typed by Next Generation Sequencing (NGS). The minimal inhibitory concentrations (MICs) were determined by Etest. A total of 2546 children with PD were identified and included in the analysis; 1233 (48.4%) with IPD and 1313 (51.6%) with non-IPD. PCVs significantly impacted disease patterns: IPD declined from 59% in the pre-PCV period to 35.1% in post-PCV13, while age distribution shifted toward older children (p < .001). All PCV7/13 serotypes decreased significantly in the post-PCV periods, except serotype 3 which increased, contributing substantially to empyema cases. Vaccine failures were 9.8% of cases, mostly attributed to serotypes 3, 19A, and 19F. Multidrug resistance (MDR) rates rose from 12.9% in pre-PCV to 24.8% in post-PCV13 period (p < .001), with MDR serotypes 19F and 23F decreasing over time and 19A becoming the predominant MDR phenotype (47.1%) in the post-PCV13 era. These findings underscore the dynamic nature of PD in the post-PCV era and highlight the ongoing need for surveillance studies, vaccine updates and resistance monitoring. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
https://doaj.org/toc/2164-5515; https://doaj.org/toc/2164-554X; https://doaj.org/article/4313eafdb9244eb28c097b5c440ae02b |
| DOI: |
10.1080/21645515.2025.2608399 |
| Availability: |
https://doi.org/10.1080/21645515.2025.2608399; https://doaj.org/article/4313eafdb9244eb28c097b5c440ae02b |
| Accession Number: |
edsbas.971F80A7 |
| Database: |
BASE |