Mapping immunization disparities among migrants in Sub-Saharan Africa: a scoping review

Migrant populations in sub-Saharan Africa (SSA) face significant disparities in immunization coverage, posing a challenge to regional disease control and herd immunity. This scoping review maps the barriers and facilitators to immunization among migrant groups in SSA. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR), a database search was conducted across eight electronic databases and grey literature from database inception to May 2025 to identify original research articles published in English. The data were screened, and the eligible articles were extracted using Covidence. Data synthesis was done numerically and thematically using the framework by Yang & Hwang (2016), categorizing barriers and facilitators using Microsoft Excel. Among the 1,292 identified records, 41 studies met the inclusion criteria. The included studies, predominantly from Kenya, Nigeria, and South Africa, cover routine immunization and specific immunization among migrants. Barriers encompassing immigrant-specific factors (nomadic lifestyles, security concerns); general resource limitations (distance to clinics, language barriers); predisposing beliefs (mistrust in health systems and vaccines); and macro-structural/systemic challenges (vaccine stockouts, weak health infrastructure). Key facilitators included community health worker engagement, mobile vaccination strategies, and integrating human and animal health services for pastoralists. Immunization disparities among migrants in SSA are driven by a complex connection between mobility, systemic inequities, and contextual barriers. Multi-level strategies, including policy changes for inclusive vaccination programs, community-led initiatives, and health system strengthening to ensure equitable access and counter misinformation, are important.