The challenge: A growing population, an outdated census, children left behind
The Democratic Republic of the Congo (DRC) has one of the world's most mobile populations, and its latest census from 1984. In the province of Haut-Katanga, in the south of DRC, lies Kafubu, a rural health zone that covers 6,000 km². With about 260,000 people across 16 health areas, Kafubu faces persistent challenges in reaching children for routine immunisation, driven largely by intense and complex population mobility.
With populations arriving continuously from Lubumbashi (the capital of the province) and surrounding health zones, as well as from other provinces, the health zone sees the influx of many families with under or unvaccinated children, including zero-dose infants.
For years, medical staff observed that population growth was outpacing official projections (based on the 1984 census), but without evidence to support this observation, vaccination targets set by the Expanded Programme on Immunisation (EPI/PEV) at central level didn't meet the reality on the ground.
Not only was it difficult to make the case for additional resources or to adjust planning, but vaccination coverage data for immunisation campaigns were being assessed against the DHIS2 denominator population, producing figures above 100% which were questioned or rejected at the provincial and national levels.
Accounting for internal mobility to improve population denominators
As a technical partner of the EPI, and thanks to our partnership with Vodacom Congo et sa Fondation, we have been producing and providing the EPI, at central, provincial and operational level, with population mobility and distribution estimates, updated monthly.
Our monthly estimates take into account short-term mobility, estimated from the mobile phone usage data, to determine internal migration and displacement trends, telling us changes in where people live, and how they move across the country, from a month to another.
This provides EPI's staff with a unique perspective on population redistribution to improve their immunisation plans, and validate their vaccination figures, for both routine immunisation and campaigns.
These data are presented to EPI's staff in the forms of reports, shared monthly, with updated maps, time series and tables for their province and relevant health zones.
Using mobility data to support vaccination: how Kafubu vaccinated more children
The Kafubu health zone, led by Dr Odile Nyota, Health Zone Chief Medical Doctor, integrated Flowminder's mobility and population estimates into its planning and advocacy processes.
The data confirmed what health staff had long suspected: the health zone had a population growth rate significantly above the national average.
The Flowminder growth rate, which includes birth, deaths and internal mobility, is 6.49% (June 2025 rate) compared to the official DHIS2 rate of 3.28% which is derived from the 1984 census projections. This gave the team quantitative evidence to bring to discussions at national, provincial, and local levels.
The estimates also enabled the team to explain, with evidence, why coverage figures calculated against DHS2 denominators exceeded 100%.
With Flowminder and its mobility reports, we observed that our growth rate was above the national average. This growth rate allowed us to readjust our planning, especially for mass vaccination campaigns, in terms of estimating vaccine needs, human resources, and logistics.
— Dr Odile Nyota, Kafubu Health Zone Chief Medical Doctor
Armed with this evidence, Dr. Nyota and her team also pursued advocacy at multiple levels.
At the national level, they made the case for additional vaccination teams, which had historically been insufficient given the actual population size. At the provincial level, they used the mobility data to reframe the discussion around coverage figures, demonstrating that high numbers reflected real population growth rather than data quality problems.
At the local level, they engaged the Bukanda decentralised territorial entity (ETD), which benefits from mining revenues.
This partnership unlocked funding to increase the number of vaccination teams and to cover logistics (such as motorcycle hire, fuel) enabling the team to reach previously inaccessible communities, and ultimately increase vaccination coverage.
The zone also expanded its vaccination strategies to meet mobile and hard-to-reach populations where they are: at fields, road toll points (a new approach, as these entry points had never previously been used for vaccination), and through village chiefs who maintain close knowledge of new arrivals.
The results have been significant.
Routine childhood immunisation coverage in Kafubu rose from 70% in June 2025 to 90% by October 2025.
A call for continued access to mobility data
Dr. Nyota and the Kafubu health team are requesting continued access to our data through 2026:
This year, we need the Flowminder data to continue into 2026 so we can compare it with 2025. We really need this data, but also in the future, if donors could consider sending us data from the health areas, that would be very valuable.
— Dr Odile Nyota, Kafubu Health Zone Chief Medical Doctor
Hear directly from the Kafubu health zone staff:
Subtitles (directly on the YouTube platform) are available in both English and French
In February 2026, our team went to Kafubu to meet with Dr Odile Nyota and her team.
Discover a few photos below:
