Zero-Dose Identification and Reach Using Electronic Community Health Records in Mozambique: A Type 2 Hybrid Effectiveness-Implementation Study Protocol

Background/Objectives Despite global progress, about 24% of children in Mozambique remain zero-dose. Geographic, socioeconomic, and systemic barriers hinder vaccine access, and caregivers often face long travel distances, stockouts, and poor service experiences. The Zero-Dose Identification and Reach initiative seeks to strengthen the Expanded Programme on Immunisation by enhancing the upSCALE digital health platform. This implementation research will evaluate the effectiveness, feasibility, and acceptability of the enhanced immunization module in identifying and vaccinating zero-dose and under-immunized children, while generating evidence for national scale-up. Methods This type 2 hybrid effectiveness-implementation study will be conducted in two districts of Zambezia Province. A non-randomized controlled trial will compare intervention (Mocuba) and control (Nicoadala) districts through baseline and endline household surveys of care-givers of children aged 3–59 months (n=440 per arm). Primary outcomes are the pro-portion of zero-dose and under-immunized children. A before-and-after survey will assess changes in knowledge, attitudes, and practices among community health work-ers. Key informant interviews and focus groups with APS, health staff, and caregivers will explore feasibility, acceptability, and scalability of the new module. Quantitative data will be analyzed using descriptive statistics and regression models, including difference-in-differences analyses while controlling for underlying secular trends between districts over time. Qualitative data will be thematically analyzed. Results Data collection will occur from September 2025 to February 2026, with findings available by mid-2026. Conclusions This study will generate evidence on the effectiveness of a digital community health platform to reduce zero-dose prevalence in Mozambique. and inform programmatic scale-up and national policy.