The Challenge
Vaccines are one of global health's greatest success stories — preventing 146 million child deaths since 1974 and generating $52 for every dollar invested. Major advances in vaccine supply, cold chain infrastructure, and delivery systems have brought lifesaving immunizations within reach of most of the world's children.
Yet 21 million children remain unvaccinated or undervaccinated today, of which 14.5 million children never receive a single vaccine dose. The vaccines exist. The delivery systems function. So why does the gap persist?
Research shows that one of the most critical barriers is low demand. Demand-side factors — information gaps, forgotten appointments, competing priorities, and behavioral barriers — drive most missed vaccinations. These barriers remain dramatically under-addressed compared to supply-side investments, despite representing one of the most urgent and cost-effective opportunities to reduce preventable child deaths.
The Opportunity
The vaccines are often available in Nigeria; however, a significant portion of the immunization gap can be attributed to demand-side barriers. The UNICEF Multiple Indicator Cluster Survey (MICS 2021) found that a substantial share of caregivers miss vaccination appointments due to awareness gaps, lack of reminders, and motivational barriers — challenges that existing interventions fail to address at scale.
The Evidence
Research from J-PAL-affiliated researchers, including Nobel Laureates Abhijit Banerjee and Esther Duflo, provides the foundation for this intervention. In large-scale randomized controlled trials covering 295,000 children in India, they demonstrated that combining simple, low-cost tools can dramatically improve immunization rates.
Note: Effect sizes were observed in the Haryana, India RCT context. The Nigeria pilot will validate whether similar results hold in a different setting. Incentives can reduce coverage in high-baseline settings; the pilot's approach is targeted to low-coverage areas.
Our Intervention
Evidence Action and the Abdul Latif Jameel Poverty Action Lab (J-PAL) are piloting a three-component intervention package designed to directly address the demand-side barriers keeping children from getting vaccinated.
| Intervention | What It Does | Barrier It Addresses |
|---|---|---|
| 1. Digital Reminders | SMS and voice messages inform caregivers about upcoming appointments and required doses | Awareness Gap: 50%+ of caregivers don't know when or where to go |
| 2. Community Ambassadors | Trusted local voices disseminate vaccine information and motivate caregivers through existing social networks | Motivation Gap: 40% cite competing priorities or low motivation |
| 3. Targeted Incentives | Small non-cash vouchers offset transportation costs in low-coverage areas | Access Gap: 12% cite distance or access barriers |
Barrier data sourced from UNICEF Multiple Indicator Cluster Survey (MICS 2021).
The Pilot
The fifteen-month pilot will reach close to 54,000 children across 150 facilities in two Nigerian states: Nasarawa (North Central region) and Ogun (South West region). These states were selected based on significant unaddressed demand-side gaps, strong government support, and the opportunity to learn from regional variation.
- Significant demand-side gaps: Approximately 40% of children in these states do not complete their third pentavalent dose; 140,000 children receive no vaccines at all.
- Strong enabling environment: Government stakeholders in both states have expressed strong support and willingness to engage in pilot co-creation and implementation.
- Regional learning: The two-state approach enables documentation of regional variation in vaccination behaviors and adaptation of the model for broad implementation across Nigeria's diverse regions.
Evidence Action estimates the cost-effectiveness of this intervention at $199 per DALY averted, which is 4.1 times better than the WHO's "highly cost-effective" threshold.
Note: The $199/DALY figure is Evidence Action's internal cost-effectiveness estimate based on modeling, not a direct result of the RCTs. The pilot will generate real-world data to validate this projection.
Partnership: Evidence Action + J-PAL
This pilot combines Evidence Action's proven capacity to deliver complex health interventions at scale with J-PAL's rigorous research expertise — a partnership model that has successfully translated evidence into scaled programs for over a decade.
J-PAL has committed the original study authors as technical advisors, including Nobel Laureate Esther Duflo (MIT), network theory expert Arun Chandrasekhar (Stanford), and Research Scientist Harini Kannan.
Evidence Action brings
- Operational infrastructure — currently operating across 90 health facilities in Nasarawa and Ogun through our prenatal vitamin pilot
- Government relationships — nearly a decade of partnership with the Nigerian government, including national scale-up of school-based deworming
- SMS/digital systems — established platforms already reaching pregnant women, the same population targeted by immunization services
- Implementation at scale — proven capacity to translate research into government-owned programs
J-PAL brings
- Research rigor & fidelity — ensures pilot design remains faithful to the RCT evidence while adapting for Nigeria's context
- Immunization demand expertise — deep operational experience with demand-side interventions and behavior change
- Policy convening power — relationships with government and experience translating research into policy action
- Monitoring system design — technical expertise in measuring program fidelity and generating credible cost-effectiveness data
The Path Forward
This pilot will generate the evidence needed to inform decisions about scaling immunization demand generation — not just in Nigeria, but across high-burden countries globally.
- 295,000 children reached through large-scale randomized controlled trials
- 26–44% increase in immunization demonstrated
- Nobel Laureate-led research informing pilot design
- 54,000 children reached across 150 facilities in two states
- Cost-effectiveness data generated to validate modeling
- Government partnership co-created for sustainability
- National expansion across Nigeria, contingent on pilot results
- Replication in other high-burden countries
- 3,000,000+ children potentially reached through national scale