From Paper to Digital: Impact of SMS-Based Reminders on Immunization Adherence in Ebolowa Health district, April – October 2025

Abstract

Introduction: Immunization is one of the most effective public health interventions for reducing childhood morbidity and mortality. This study assessed the effect of transitioning from a paper-based reminder system to an SMS-based digital reminder system on immunization adherence among children aged 0–59 months in the Ebolowa Health District.

Methods: A quasi-experimental pre-post study was conducted from April to October 2025 in fifteen health facilities in the Ebolowa Health District. During the baseline phase, vaccination adherence data were collected under the routine paper-based system. The intervention phase introduced automated SMS reminders sent to caregivers 48 hours before and on the day of scheduled vaccination appointments. Quantitative indicators included timeliness of vaccination, missed appointments, and completion rates, while qualitative data were obtained from caregivers and health workers. Statistical analyses used Chi-square tests, t-tests, and logistic regression, with significance set at p < 0.05.

Results: The SMS reminder intervention significantly improved immunization adherence. On-time vaccination increased from 63.7% to 85.2%. Coverage for Penta 1 rose from 529 to 713, and Penta 3 from 532 to 622. Catch-up activities identified 1,973 zero-dose children and 1,337 under-vaccinated children. SMS delivery success reached 99%, and overall satisfaction was high (95%). Caregiver recall reduced missed appointments, and increased confidence in the system, despite challenges such as network instability.

Conclusion: SMS-based reminders improved immunization adherence and coverage in the Ebolowa Health District. Integrating digital reminder systems into Cameroon’s national immunization program could enhance vaccination monitoring.