Spatio-temporal dynamics, transmission hotspots, and vaccination gaps driving measles persistence in Nigeria, 2006–2025

BACKGROUND: Measles remains a major public health concern in Nigeria, contributing disproportionately to the global burden. Persistence of the disease is driven by sub-optimal vaccination coverage and heterogeneous transmission patterns, but the specific spatio-temporal dynamics and the quantitative impact of vaccination gaps at the sub-national level are not fully characterized. OBJECTIVE: This study aimed to provide a comprehensive analysis of measles transmission in Nigeria from 2006 to 2025, with the specific objectives to identify spatial hotspots, quantify their temporal persistence, and evaluate the association between MCV1/MCV2 coverage and measles case ratio. METHODS: We conducted a national retrospective ecological study, integrating 19 years of surveillance data (2006-2025) and geospatial information, with a focused 4-year analysis of vaccination records (2021-2024). Analytical methods included time-series decomposition, spatial autocorrelation (Local Moran's I and Getis-Ord Gi*), and linear mixed-effects modeling to quantify vaccination effects while accounting for state-level heterogeneity. RESULTS: Analysis of 253,595 measles cases revealed a highly clustered geographic distribution, with 86.4% of the national burden concentrated in northern Nigeria. We identified 38 persistent hotspot Local Government Areas that accounted for 23.2% of all cases. Vaccination coverage was low and disparate, with national averages of 73.8% for MCV1 and 38.4% for MCV2. Mixed-effects modeling confirmed a significant negative association between MCV1 coverage and the measles case ratio, while MCV2 coverage did not show a statistically significant independent effect. CONCLUSION: Measles transmission in Nigeria is driven by entrenched hotspots in the north and critical vaccination gaps threatening disease resurgence in the south. Achieving elimination requires a tailored strategy: intensive supplemental immunization activities and RI strengthening aimed at reducing endemic transmission in the northern hotspots, coupled with focused efforts to close routine immunization gaps in specific southern states.