Digital vaccines for immunization equity: an approach to strengthen vaccine delivery and public trust in low- and middle-income countries.

Background: Global immunization efforts still face major inequities and declining vaccine confidence, leaving millions of children in low- and middle-income countries unvaccinated or under-vaccinated. Objectives: This article aims to discuss "digital vaccines," including SMS reminders, mobile apps, electronic immunization registries, gamification, and virtual reality education, as practical complements to routine immunization services. Results: Using an organizing framework focused on access, equity, and trust, we highlight how digital tools can reduce missed appointments, strengthen follow-up for zero-dose children, improve data quality for planning, and support transparent and culturally responsive communication to counter misinformation. We also outline the barriers that limit equitable impact, including digital divides, gender gaps in phone access, fragmented information systems, limited financing, and concerns about data governance. Many children in poorer countries still do not get the vaccines they need. Some families live too far from clinics. Others do not trust vaccines or the health system. This article looks at how digital tools can help more children get vaccinated. These tools include text message reminders, phone apps, online health records, digital games, and virtual reality lessons. Text reminders help parents remember vaccine dates. Online records help health workers find children who missed their vaccines. Digital games teach people why vaccines are safe. These tools can also help planners know how many vaccines are needed and where to send them. They can share clear, respectful health messages and fight false claims about vaccines. But not everyone can use these tools. Some people do not have smartphones or internet access. Women, who often care for children, may not have their own phones. There are also worries about keeping personal data safe and paying for these systems. Conclusions: We propose implementation principles that emphasize inclusive design, interoperability, privacy safeguards, and hybrid online and offline delivery models. We suggest that digital tools should be easy to use for all, keep private data safe, and work well with other health systems. Where there is no internet, non-digital options should also be offered. With the right support, these tools can help make sure all children get their vaccines.