Despite the impressive economic progress in developing countries, significant proportion of young children and pregnant women living in low-resource settings remain inadequately immunized. Progressive decline in immunizations are in large part attributable to poor follow-up and compliance. National and international pediatric bodies, recommend a time sensitive schedule for childhood immunizations, boosting immunity with each subsequent cycle, leading to adequate levels of immune protection. Due to inadequate protective immunity, resulting from poor vaccination compliance, outbreaks of vaccine-preventable diseases are rampant, making childhood mortality in this group among the highest in the world. Major challenges of vaccination programs include maintaining / tracking records, linked to positive identification of individual children, and strategies to improve follow-up and compliance. Novel cellular technology based approaches targeting behavior modifications can therefore significantly impact health outcomes in these communities. In this proposal, the investigators will evaluate a novel software platform, utilizing biometric identification of subjects, paired with cell-phone reminders and compliance-linked incentives to improve uptake and coverage of primary vaccinations in young children and pregnant women.