Review of Polio Immunisation Campaign Coverage and Strategies in Adamawa State

Despite Nigeria's certification as wild poliovirus-free in 2020, circulating vaccine-derived poliovirus type 2 outbreaks continue to challenge the North East zone, making high polio immunisation coverage a sustained priority. This study reviews the coverage levels and operational strategies of polio immunisation campaigns conducted in Adamawa State between 2021 and 2024. A retrospective review of National Immunisation Plus Days (NIPDs) and Outbreak Response Immunisation (ORI) campaign reports from the Adamawa State Primary Health Care Development Agency will form the primary data source. Campaign coverage data disaggregated by local government area, vaccine type (nOPV2, bOPV), and target age group will be analysed against WHO minimum coverage thresholds. Independent monitoring reports from the National Primary Health Care Development Agency and UNICEF will be reviewed for missed children data and refusal cluster mapping. Key informant interviews with immunisation programme officers will provide contextual insights on operational challenges encountered during campaigns. Recent GPEI data indicate that vaccine refusal, hard-to-reach communities, and insecurity continue to prevent sustained high coverage in Adamawa's southern local government areas. Findings will characterise immunisation campaign performance in Adamawa State, identify persistent coverage gaps, and recommend operational improvements for enhancing campaign quality and community acceptance. Keywords: polio immunisation, campaign coverage, Adamawa State, nOPV2, vaccine-derived poliovirus