Interventions to improve vaccination coverage among children aged 12-23 months in urban slum areas of Asia: A systematic review and meta-analysis
In brief
Two trials found vaccination programs raised children's DPT3 vaccination odds 2.7-fold
In two randomized trials, children in intervention groups had about 2.7 times the odds of receiving the third dose of diphtheria, pertussis and tetanus vaccine. Across nine studies involving 37,405 children, strategies also improved other coverage measures, but bias, inconsistent results and questions about long-term sustainability limit confidence in their real-world impact.
- Journal
- Global health research and policy (Q1)
- Published
- 12 August 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Kazi Fayzus Salahin, Ricvan Dana Nindrea, Quazi Monirul Islam, Tippawan Liabsuetrakul
- PMID
- 42990976
- DOI
- 10.1016/j.ghrp.2026.08.002
Why clinicians should know about it
- Picked for Epidemiology (paper of the day, 7 November 2026): Systematic review evaluates population vaccination programme interventions
- Picked for Public Health, Environmental and Occupational Health (paper of the day, 7 November 2026): Systematic review evaluates child vaccination coverage interventions
Abstract
BACKGROUND: Low vaccination coverage among children in slum areas is a global concern, particularly in Asian countries. Despite several reported studies, systematic reviews are lacking. This systematic review aimed to identify interventions that effectively improve vaccination coverage among children aged 12-23 months in slum areas in Asia. METHODS: We searched the Embase, PubMed, and Cochrane databases using specific search terms for articles published between 2010 and January 2026. Two investigators independently extracted the data and assessed the methodological quality of the identified studies. Biases in non-randomized and randomized studies were assessed using the Risk of Bias In Non-randomized Studies of Interventions and Risk of Bias 2 tools, respectively. The quality of the evidence was assessed using the Grading of Recommendation, Assessment, Development, and Evaluations tool. Heterogeneity was assessed using I2, and subgroup analysis was performed when substantial heterogeneity was identified. The effect measure was estimated using odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The nine included studies ranged from quasi-experimental to randomized controlled studies (RCTs) conducted in Bangladesh, India, Indonesia, and Pakistan, involving 37,405 children. The included studies demonstrated a moderate to high or serious level of bias. The full vaccination coverage probably improved in only one RCT (OR 6.42, 95% CI 4.63-8.90) and from three quasi-experimental studies (OR 9.68, 95% CI 3.91-23.95) with high heterogeneity. DPT3 vaccine coverage significantly improved in two RCTs (OR 2.68, 95% CI 2.17-3.31; 1872 participants; I² = 0%), whereas quasi-experimental studies showed uncertain effects with high heterogeneity (OR 3.58, 95% CI 2.99-4.28; 31,817 participants; I² = 78%). Compared to the control groups, single or multicomponent strategies significantly increased vaccination coverage. However, the certainty of the evidence was moderate in RCTs and very low in quasi-experimental studies owing to methodological limitations. CONCLUSIONS: Owing to the methodological biases of the included studies and the limited sustainability of the implemented interventions, further studies are needed to improve vaccination coverage in children aged 12-23 months, particularly in slum areas of Asia.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.