Systematic review of pro-equity strategies to improve vaccination among priority populations

The importance of pro-equity strategies in addressing disadvantages that people and communities face due to their gender, migration status, ethnicity, disability, and place of residence is increasingly being recognised, but analysis of empirical evidence on how they improve vaccination in these priority groups is limited. This systematic review aims to fill this gap.

Standard evidence synthesis methods were employed, with searches conducted in four major bibliographic databases in March 2025. Studies were included if they reported on strategies aimed at improving vaccination uptake, coverage, and/or timeliness among priority groups disadvantaged by gender, migration status, disability, ethnicity, or geographical location, with no exclusions based on language, time, or type of vaccination. Excluded studies were those without explicit intervention or outcome data related to vaccination and those not focused on the identified priority groups or settings. A thematic analysis was conducted to map strategies for immunisation programmatic areas. Strategies were also mapped to the Tanahashi coverage framework, which identifies how pro-equity strategies addressed bottlenecks in the delivery of immunisation programs.

From 20,812 records retrieved, we identified 59 studies showing pro-equity strategies that improved vaccination uptake or coverage (n = 54) and timeliness (n = 6). Twenty-five pro-equity vaccination strategies under five immunisation system domains were studied. Thirty-nine studies were conducted in high- and middle-income countries. Most (56 %) focused on community-oriented strategies and improving acceptability (63 %). Few targeted upstream system-level barriers, such as policy and governance (n = 7), availability (n = 5), or effectiveness (n = 10) of immunisation service delivery. No single strategy or approach was universal across the priority groups. However, some approaches were more common in specific populations and settings.

This review synthesises strategies to address vaccination inequities among underserved populations. Achieving vaccination equity will require context-specific approaches to address individual and systemic barriers across community engagement, service delivery, information systems, and policy and governance.