Submission ID 131825
| Issue/Objective | Childhood vaccination coverage declined to 72% in Katete District, Zambia in 2024, below the national target of 82%. While Electronic Immunization Records (EIR) and Short Message Service (SMS) reminders have shown potential to improve vaccination outcomes, evidence from district-level implementation in sub-Saharan Africa remains limited. This study assessed the effectiveness of SMS reminders on vaccination uptake, series completion, and dropout rates in the rural Katete District, Eastern Province, Zambia. |
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| Methodology/Approach | A non-randomized controlled trial was conducted at two health facilities: Chibolya Health Post (intervention arm: EIR + SMS reminders sent prior to and on the appointment day, n=133) and Mpangwe Health Post (control arm: usual care, n=147). A total of 276 parent-baby units were enrolled and followed for 9-months. Primary outcomes were vaccination rate per scheduled visit and vaccine series completion (birth through 14-weeks). Secondary outcomes included completion through 9-months and inter-visit dropout. Chi-square tests with Risk Ratios and Mann-Whitney U tests were used for between-group comparisons (p<0.05). Data were tracked using the District Health Information Software 2 (DHIS2). |
| Results | Among 276 infants receiving a birth dose, vaccination rates declined across subsequent visits, reaching 21.4% (59/276) at 9 months. The control group had significantly higher vaccination rates at 6-weeks (59.0% vs 41.0%), 10-weeks (60.8% vs 39.2%), and 14-weeks (63.4% vs 36.6%) visits (all p<0.05). Primary series completion (birth through 14 weeks) was significantly higher in the control group (71.1% vs 39.6%; RR 0.51, 95% CI 0.39-0.67; p<0.05). There was no significant difference in completion at 9-months (29.4% vs 14.2%; p=0.17). Dropout was significantly higher in the intervention group between birth and 6-weeks interval (32.1% vs 7.7%; p<0.005) and between 10 and 14 weeks (30.8% vs 15.7%; p=0.012). |
| Discussion/Conclusion | SMS reminders alone did not improve vaccination attendance or series completion and were associated with higher dropout at key intervals, compared to usual care in this trial. More comprehensive strategies beyond one-way SMS reminders are likely needed to improve immunization outcomes in similar settings. |
| Presenters and Affiliations | Adon Chawe St Francis Central Hospital Rex Wong University of Global Health Equity (UGHE) Ziad El-Khatib Department of global health, Karolinska Institzutet |
