New findings from the Zero-Dose Learning Hub supported by Gavi, the Vaccine Alliance show that many under-immunised children remain unseen due to aggregated data, fragmented health information systems, and assumptions made at national levels. The evidence suggests that improving immunisation coverage requires not only better data and funding but also stronger accountability and strategies tailored to local realities.
As the global learning partner for the initiative, JSI analysed research from Country Learning Hubs in Bangladesh, Mali, Nigeria, and Uganda. The analysis highlights how routine reporting systems can obscure the true scale of zero-dose children—those who have not received even a first routine vaccine—while institutional challenges often determine whether immunisation strategies succeed.
The research shows that the burden of zero-dose children is dynamic and highly localised, yet it is often hidden in national or district-level data reporting systems. Many immunisation programmes rely on administrative data platforms such as DHIS2 to guide planning and resource allocation. However, when data is aggregated at higher levels, smaller pockets of under-immunised children can disappear from view. Evidence from Bangladesh found that zero-dose hotspots shifted from year to year, indicating that static national estimates may fail to capture rapid changes caused by workforce disruptions, vaccine supply interruptions, or other systemic shocks. In some cases, administrative coverage even exceeded 100 percent due to outdated population estimates or children receiving vaccinations outside their registered areas, creating a misleading picture of strong coverage.
In Nigeria, a decentralised immunisation monitoring approach using lot quality assurance sampling revealed stark differences in vaccination performance at subdistrict levels, particularly between rural wards and urban areas. This demonstrates the need for more granular monitoring systems that can detect shifting zero-dose hotspots during Gavi’s 2026–2030 strategic period.
Another major challenge identified by the Learning Hub is the fragmentation of health data systems. Many countries operate multiple donor-supported tools and parallel reporting platforms that do not easily connect with each other. In Mali, the use of different systems, including DHIS2, paper records, and programme-specific tools, made it difficult for district teams to track children over time and coordinate follow-up services. This fragmentation increases workloads for frontline health workers and slows down decision-making, particularly in areas where immunisation gaps are most severe.
The findings also highlight that barriers to vaccination are not only geographic but often social. Household decision-making dynamics, gender norms, poverty, and misinformation can strongly influence whether children receive vaccines. In several Learning Hub countries, caregivers’ agency and social structures were found to play a major role, meaning that strategies focusing solely on physical access to services may overlook critical behavioural and social factors.
Costing studies from the research further show that reaching zero-dose children requires more precise budgeting rather than broad national estimates. In Uganda, the cost of delivering the first dose of the diphtheria, tetanus, and pertussis vaccine varied widely between districts—from about $8.30 in one rural area to $68.70 in a mountainous region—depending on factors such as geography, population density, and delivery methods. These differences indicate that uniform funding models can lead to inefficiencies, with some areas overfunded while others remain under-resourced.
The research also points out that local innovations aimed at improving immunisation coverage can be undermined by systemic issues such as delayed operational approvals, vaccine shortages, and workforce instability. In Bangladesh, for example, high vaccinator vacancy rates and delayed payments weakened efforts to identify and reach zero-dose children, while in Mali insecurity limited data collection in some districts, suggesting that the actual number of missed children could be higher than reported.
Another key insight is that the effectiveness of data depends heavily on institutional conditions. In Nigeria, immunisation accountability scorecards helped draw political attention and unlock previously delayed budgets, demonstrating how data can influence action when linked to governance structures. However, in Uganda, frontline teams were able to identify missed children but lacked the authority and resources to ensure follow-up vaccinations, leaving many still unvaccinated a year later.
As global health financing becomes more constrained and planning continues for Gavi’s 2026–2030 strategy period, these findings provide guidance for strengthening immunisation systems. Experts emphasize the need to improve visibility at subdistrict levels, integrate fragmented data systems, address social and household barriers to vaccination, tailor budgets to local delivery realities, and reinforce governance mechanisms so that evidence leads to timely action. JSI is continuing to consolidate lessons from the Learning Hubs to help countries and partners refine priorities for the next phase of immunisation efforts under Gavi’s future programmes.
