The African Field Epidemiology Network (AFENET), a non-profit organisation, recently used Google’s Open Buildings dataset to locate previously unmapped villages in Nigeria, uncovering communities where thousands of children had never received a single vaccine dose.
Through this effort, 78,000 previously unreached children in Yamma 2 ward of Katsina State were identified and vaccinated. The Open Buildings dataset, an open AI dataset of 1.8 billion building footprints, was developed by Google Research Africa and is now helping close health gaps and safeguard flood-prone neighbourhoods across the continent.
According to Google, the dataset is being used in countries including Rwanda, Nigeria, Kenya, and South Africa to locate zero-dose children, plan rural health infrastructure, and design city-level flood protection plans.
Nigeria is home to 2.1 million children who have never received any form of vaccination, largely because many settlements do not appear on official maps, according to global vaccine alliance Gavi.
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To address this, AFENET Nigeria collaborated with the University of Southampton and Katsina State Primary Health Care Development Agency to implement a proof-of-concept project in Yamma 2 ward of Katsina Local Government Area. Using geographic information system (GIS) tools, they worked to identify and map households with children under the age of five.
Epidemiologists from AFENET and demographers from WorldPop, a research group based in the University of Southampton’s School of Geography and Environmental Science, combined high-resolution satellite building footprints with road and settlement data to uncover villages missing from census records.
They verified 10,250 buildings in Yamma 2 ward of Katsina state,enabling health workers to plan and execute targeted outreach using the new coordinates. Over a six-month period, vaccinators reached more than 70 percent of children who had never received a dose of DPT, measles, or polio vaccine, cutting zero-dose prevalence by up to 65 percent in the ward.
According to Google, these mapped settlements are now stored in the national database, so they remain on the radar for future health and nutrition programmes.
“Open Buildings gives us the roof-level detail to build accurate population grids where traditional data are missing. Overlaying those grids with vaccine-coverage maps lets our joint WorldPop–AFENET teams pinpoint zero-dose pockets and guide vaccinators street by street, so no child is missed,” said Edson Utazi, associate Professor of Spatial Data Science, WorldPop, University of Southampton.
“These projects show what happens when local expertise meets open, scalable technology: mothers reach clinics sooner, children receive long-overdue vaccines, and city planners get ahead of the next flood. We’re thrilled to stand beside partners who turn data into decisive action, proving that AI’s highest calling is to solve real-world challenges,” added Aisha Walcott-Bryant, research scientist and head, Google Research Africa.
