Closing the Immunization Gap: How Digital Tracking Is Reaching Unvaccinated Children

Vaccines are among the most cost-effective public health interventions ever developed. Measles vaccination alone has prevented an estimated 21 million deaths since 2000. Yet in 2024, UNICEF reported that 14.5 million children in Africa remained completely unvaccinated — the so-called 'zero-dose' children — and millions more had incomplete immunization schedules.

The problem is rarely vaccine supply. It is tracking. Paper-based immunization cards are lost, damaged, or never issued. Families relocate between clinic visits. Children who miss their second or third dose in a multi-dose schedule fall through the cracks, with no system to alert a health worker or remind a caregiver. The dropout between first and third doses of pentavalent vaccine in some high-burden countries exceeds 20%.

Digital immunization registries offer a solution. By assigning each child a unique digital health identifier at birth or first contact, linked to a caregiver's phone number, the system can automatically generate reminders for upcoming vaccination appointments, alert health workers when a child is overdue, and flag zero-dose children for outreach.

Be Okay's mother and child health module, launched in partnership with three district health authorities in 2025, has enrolled 47,000 children under two in digital immunization tracking. In the first six months, the system generated 92,000 automated reminders to caregivers and flagged 3,200 children as overdue for urgent follow-up by community health workers.

Immunization coverage rates in enrolled districts increased from 71% to 88% for the third dose of pentavalent vaccine over the same period — a 17-percentage-point improvement that, if sustained and scaled, would translate to hundreds of thousands of additional fully vaccinated children per year.

Beyond the numbers, the digital registry creates a longitudinal health record for each child — a foundation that can support growth monitoring, nutrition intervention, school health programs, and, eventually, a lifelong health record. The immunization card is not just a vaccine tracker. It is the beginning of a health identity. Every child deserves one.