Childhood immunization is one of the most cost-effective public health interventions, yet incomplete vaccination schedules persist globally, especially in low-resource settings. Missed appointments due to forgetfulness, lack of information, or logistical challenges contribute significantly to low coverage rates, leaving children vulnerable to preventable diseases. Mobile health (mHealth) technologies, particularly widely accessible SMS reminders, offer a scalable, inexpensive, and effective tool to bridge communication gaps and improve adherence to critical immunization schedules, thereby directly impacting child survival and public health outcomes in vulnerable populations.
The aim of the study.
This study aimed to determine the effectiveness of an mHealth-based SMS reminder system in improving adherence to the routine childhood immunization schedule (specifically DPT-HepB-Hib series) in pediatric populations residing in low-resource rural communities of India and Kenya.
Material and methods.
A cluster-randomized controlled trial was conducted over an 18-month period involving 1,200 mother-child dyads (child age <3 months at enrollment) across 20 primary health centers (PHCs) in rural regions of India (n=10 PHCs) and Kenya (n=10 PHCs). PHCs were randomized 1:1 to either the mHealth intervention arm (n=600 dyads) or the standard care control arm (n=600 dyads). In the intervention arm, mothers received three automated SMS reminders per scheduled vaccination dose: one a week prior, one two days prior, and one on the day of the appointment, followed by a missed appointment reminder if necessary. Reminders were in local languages. The control arm received standard immunization counseling from PHC staff. The primary outcome was the completion rate of the full DPT-HepB-Hib series (3 doses) by 12 months of age. Secondary outcomes included the number of missed appointments and caregiver satisfaction. Statistical analysis involved mixed-effects logistic regression to account for clustering at the PHC level, with significance set at p < 0.05.
The mHealth reminder group demonstrated a significantly higher completion rate for the full DPT-HepB-Hib immunization schedule (88.2%) compared to the control group (65.4%) (Adjusted Odds Ratio 3.8, 95% CI 2.9-4.9, p < 0.001). The number of missed appointments per child was significantly lower in the intervention group (mean 0.3 ± 0.2) compared to the control group (mean 1.1 ± 0.4) (p < 0.001). Caregiver satisfaction with the reminder system was high, with 95% reporting the messages as helpful or very helpful. No adverse events related to the mHealth intervention were reported. Data showed that 70% of mothers in the intervention group received all scheduled messages, with an estimated 90% SMS delivery success rate.
mHealth-based SMS appointment reminders are a highly effective, scalable, and low-cost intervention for significantly improving adherence to routine childhood immunization schedules in low-resource settings. By directly addressing common barriers like forgetfulness and lack of timely information, these interventions contribute substantially to increased vaccination coverage and improved child health outcomes. Policy makers and public health organizations should prioritize the integration of such mHealth strategies into national immunization programs to maximize their reach and impact globally.
1. Dubois C, Martin L. mHealth for vaccination: A review of global efforts. J Global Health. 2023;13:04001.
2. Kumar R, Gupta A. Improving immunization rates in India: The role of mobile technology. Indian J Public Health. 2022;66(3):289-295.
3. Musa A, Kimani J. Mobile reminders for child health in Kenya: A field study. East Afr Med J. 2021;98(4):254-260.
4. World Health Organization. mHealth: New horizons for health through mobile technologies. Geneva: WHO; 2011.
5. G. Ndlovu. Digital solutions to advance child health in Africa. Afr J ICT. 2024;11(1):1-10.