Background: The COVID-19 pandemic has exacerbated global health inequities, with low-income countries lagging behind in vaccine coverage. By late 2023, only 36% of Kenyans had received at least one vaccine dose, far below the African Union 60% target. This study examines spatial disparities in COVID-19 vaccination rates across Kenya, exploring how socioeconomic, environmental, and healthcare infrastructure factors shape vaccine access. Unlike previous studies focused on individual determinants, this research employs a spatial epidemiological approach to uncover structural barriers to equitable vaccination. Methods: This study uses data from the 2022 Kenya Demographic and Health Survey (KDHS), integrating socioeconomic, health, and environmental variables across 1,692 georeferenced clusters. Analytical methods include spatial clustering (K-Means), spatial autocorrelation (Moran I), Random Forest regression, and the Erreygers Concentration Index (ECI) to quantify vaccine inequities. A Development Index (DI) was constructed to assess how financial access, living conditions, and healthcare systems influence vaccination rates. Results: Our results reveal stark geographic disparities: vaccination rates range from 5.93% in Garissa to 46.02% in Nyeri, with urban clusters achieving significantly higher coverage. Key predictors include bank access (financial inclusion), household crowding, and environmental factors (Nitrogen dioxide levels, precipitation). Wealth-based inequities (ECI = 0.044) were more pronounced than immunization-linked disparities (ECI = 0.025), highlighting financial barriers as the primary exclusionary factor. Conclusions: This study underscores the need for targeted interventions, including mobile vaccination units, financial inclusion programs (e.g., M-Pesa subsidies), and integration of COVID-19 vaccines into routine immunization programs. Findings offer a replicable geospatial framework for low- and middle-income countries (LMICs), providing data-driven policy recommendations to enhance vaccine equity and pandemic preparedness. Addressing these disparities requires multisectoral approaches that integrate health system strengthening, financial accessibility, and climate resilience to ensure equitable vaccine distribution in vulnerable populations.

The authors have declared no competing interest.

This study did not receive any funding

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Data are available in a public, open-access repository. The data that support the findings of this study are available from the Demographic and Health Surveys (http://www.measuredhs.com), but restrictions apply to the availability of these data, which were used under license for the current study and so are not publicly available. However, data are available from the authors on reasonable request and with the permission of Demographic and Health Surveys. We sought and were granted permission to use the core data set for this analysis by Measure DHS.

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