Mapping DTP1,3 and MCV1 coverage and zero-dose prevalence in Nigeria: A spatiotemporal analysis (2000 - 2024)

Spatially detailed estimates of childhood vaccination coverage are crucial to guide program design, targeting interventions, and evaluating progress within countries. In settings where substantial geographic inequities persist, high-resolution vaccination coverage and corresponding zero-dose maps can be helpful for understanding local patterns and informing strategies to reach underserved or missed populations. In this study, we produce annual 1x1 km and district level estimates of coverage for the first and third doses of diphtheria-tetanus-pertussis vaccine (DTP1 and DTP3) and the first dose of measles-containing vaccine (MCV1), as well as zero-dose prevalence, across Nigeria from 2000 to 2024. Our analyses draw on data from five Demographic and Health Surveys and two Multiple Indicator Cluster Surveys conducted between 2003 and 2024, alongside a suite of geospatial covariates. We fitted and evaluated Bayesian geostatistical models using the INLA-SPDE framework applied to cluster-level survey data. The resulting estimates highlight a persistent north-south divide in coverage, with consistently lower rates in the northern regions across the study period. Minimal gains were observed prior to 2015, followed by marked improvements that peaked in 2019 and declined slightly thereafter, with Jigawa and Yobe showing more sustained progress. We estimate that more than two million zero-dose children reside in Nigeria each year, with the highest burdens concentrated in the northeast, northwest, and parts of the south. These high-resolution outputs provide critical evidence to support subnational prioritization, strengthen routine immunization, and accelerate progress toward equitable vaccination coverage and disease elimination in Nigeria. What is already known on this topicO_LIVaccination is one of the most successful public health interventions, saving millions of lives each year and making a major contribution to child survival. C_LIO_LIHowever, substantial gaps in vaccination coverage remain, particularly among children living in low- and middle-income countries (LMICs). C_LIO_LIZero-dose and under-vaccinated children remain vulnerable to vaccine-preventable diseases and reaching them is crucial to prevent disease transmission and outbreaks. C_LIO_LIReliable, current and spatially detailed evidence on coverage and the sizes and geographical distribution of zero-dose children is often unavailable in many LMICs, making the design of targeted interventions more challenging. C_LI What this study addsO_LIWe employed Bayesian geostatistical modelling approaches to produce annual vaccination coverage and zero-dose estimates for Nigeria at 1x1 km resolution, the district and other administrative levels, covering the period from 2000 to 2024 (including predictions for 2025). C_LIO_LIOur results showed substantial heterogeneities and a persistent north-south divide in coverage. These also revealed that more than two million zero-dose children reside in Nigeria each year, with the highest burdens concentrated in the northeast, northwest, and parts of the south. C_LI How this study might affect research, practice or policyO_LIOur outputs can be triangulated with subnational administrative data for data quality assessments and other complementary datasets, such as travel time to the nearest health facility, to produce additional operationally relevant outputs. C_LIO_LIUsing these outputs, program managers and policy makers can plan and implement targeted interventions to reach zero-dose and under-immunized children, hence accelerating progress towards Immunization Agenda 2030 goals in Nigeria. C_LI