Health campaign data collection has traditionally been treated as a one-off exercise: once a vaccination round ends, the microplans, population estimates, and geographic records it produced are largely set aside. In Cameroon, a different approach has taken hold. Since 2023, data collected during a national measles campaign has been reused, enriched, and extended across 16 subsequent malaria and immunization campaigns, 9 of which were completed at zero additional collection cost. This is what campaign data reuse looks like at scale.
In 2023, a GAVI innovation grant provided the opportunity to introduce IASO, Bluesquare’s data collection and microplanning platform, to support Cameroon’s national measles campaign. Beyond monitoring the campaign itself, the initiative included a structured microplanning phase designed from the outset to produce reusable outputs.
Teams collected a comprehensive geo database covering health facilities, health areas, and districts across the country. Alongside this geospatial layer, the system captured granular population estimates by age group and zone type, logistics data including cold chain equipment inventories, and contact information for health area managers. Rather than filing these away at the end of the campaign, the Ministry of Health and its partners treated this dataset as the foundation for a living georegistry at national level.
Through IASO’s registry and mobile tools, Cameroon’s Ministry of Health has moved from one-off data collection to a continuously maintained data system. Three features make this possible.
IASO consolidates data collected across previous campaigns into a single interface. Program managers can view population figures, contact numbers, cold chain equipment inventories, and facility coordinates without navigating multiple systems or rebuilding spreadsheets. The system preserves historical records even when administrative boundaries evolve, such as during region splits, making it possible to maintain a continuous record across administrative changes.
The logic is straightforward: identify what has changed since the last campaign and update only what is necessary, rather than recollecting everything from scratch.
A mobile change request system allows any participant in the program to flag a discrepancy or submit a formal update directly from the IASO app. Those requests are reviewed and validated through the web platform, organized by region to allow decentralized governance without losing central oversight.
This mechanism turns field agents into active contributors to data quality, creating a continuous feedback loop between the people working in communities and the managers responsible for planning the next campaign.
Once reference data is maintained in the system, IASO can generate microplanning documents automatically, following official Ministry of Health templates. Health area managers can download their microplan, complete with maps, population targets, and logistics data, directly from the platform and on demand. A process that previously required weeks of manual compilation becomes an instant, reproducible output.
Between May 2023 and December 2025, the Ministry of Health and its partners ran 17 operational steps spanning national and sub-national scopes: measles, polio, yellow fever, Seasonal Malaria Chemoprevention (SMC), malaria RTS,S, and insecticide-treated mosquito net (LLIN) distribution. Of the 16 campaigns that followed the initial georegistry deployment, 9 were completed with zero microplanning data collection costs. The geo data already existed; it simply needed to be activated for each new round.
Where data collection was required, whether for validation updates, new geographic scopes, or large-scale refreshes, costs remained far below published benchmarks. This reflects a compounding dynamic: each campaign that contributes to and draws from the shared registry reduces the cost and effort of the next one.
The value of a maintained georegistry does not stop at campaign planning. In Cameroon, the same data assets have been repurposed for population modeling, epidemiological analysis, and automated risk assessment.
Micro-census data collected across 6 campaigns was consolidated into a single national dataset and shared with WorldPop for population modeling. The resulting national and sub-national population estimates, disaggregated by age group, directly informed Cameroon’s GAVI proposal and are planned for integration into the campaign management platform ahead of 2026 campaigns.
These updated estimates were combined with case-based measles surveillance data to identify districts with unusually high incidence among children aged 5 to 9 years. The findings were used to prioritize districts for supplemental immunization activities (SIAs) and incorporated into Cameroon’s GAVI proposal as evidence for sub-national tailoring of vaccination efforts.
Bluesquare supported the Ministry of Health in building automated pipelines to routinely produce risk maps based on WHO’s Measles Risk Assessment Tool (MRAT), building on the Epimaps approach already deployed in Cameroon. Once validated with the national Expanded Programme on Immunization (EPI), these maps would guide resource allocation ahead of each campaign cycle.
The Cameroon experience demonstrates what becomes possible when campaign data is treated as a long-term institutional asset. By maintaining a living, interoperable registry that grows with each successive campaign, program managers can shift their attention from the logistics of data collection to the analysis and decisions that data enables. The investment in a solid data infrastructure, refreshed incrementally through each campaign, compounds over time: each round adds to the shared asset, making the next one faster, cheaper, and more precisely targeted.
