Abstract
Osun State has one of the lowest routine immunisation coverages in Southwest Nigeria, yet no comprehensive review exists that maps the specific barriers operating within the state. To systematically map the evidence on barriers to routine childhood immunisation in Osun State, identify knowledge gaps, and propose research and policy priorities. Arksey and O’Malley’s scoping review framework was used. PubMed, AJOL, Google Scholar, and grey literature were searched from 2015–2024 using terms related to immunisation barriers and Osun State. Only 11 studies conducted in Osun State met inclusion criteria. Dominant barriers identified were religious/cultural misconceptions (6/11 studies), poor maternal knowledge of schedule (8/11), long distance to facility (5/11), negative health worker attitude (4/11), and vaccine stock-outs (3/11). No study was found in Ede North, Ife North, or Boluwaduro LGAs. No qualitative study explored religious leader perspectives in Osun State. Evidence on immunisation barriers in Osun State is scanty, outdated, and geographically skewed. Large parts of the state remain research deserts. Urgent primary studies are needed in the worst-performing LGAs using mixed-methods designs and community-engaged approaches.