Implementation Research Zero-dose and Under-immunized Children - NCT07928115

Background: This protocol describes both a broader development initiative to address the needs of "zero-dose" (ZD) and under-vaccinated children, and embedded research. The embedded research includes primary data collection through interview and group discussions, and formal implementation research activities. All are funded by Gavi, the vaccine Alliance to generate timely information products for use in tailoring immunization strategies, and in tracking progress in reducing the numbers of ZD and under-vaccinated children. Every year, nearly 10 million of the 72.5 million children that Gavi aims to reach in low-income countries do not receive a single dose of vaccine. Thus, these children are left susceptible to some of the world's deadliest diseases. The zero-dose (missing first dose of pentavalent vaccine) children account for nearly half of all vaccine-preventable deaths in Bangladesh. Approximately, 45% of the 9.7 million zero-dose (ZD) children reside in urban/peri-urban, remote rural or conflict settings of the country. Notably, about 16-20% of Bangladeshi population remain continuously unvaccinated or under-vaccinated which leaves critical gaps in protection and renders vulnerability to outbreaks. Gavi and the Global Immunization Agenda 2030 have greatly intensified their emphasis on equity, intending to reach ZD, under-immunized (missing third dose of pentavalent vaccine) children and their communities. Gavi's new five-year strategy 5.0 to improve equity in vaccination coverage hinges on five key intervention areas within the Identify, Reach, Monitor, Measure, and Advocate (IRMMA) framework. To support this, Gavi is setting up "Gavi zero-dose country learning hubs" in order to identify and select a consortium of partners for implementing the learning hubs in Bangladesh, Mali, Nigeria and Uganda. The functioning of a country learning hub in each study country will ensure increased and timely availability of evidence to meet needs prioritized by country level stakeholders and that are aligned with Gavi learning priorities. Therefore, the ZD country learning hub in Bangladesh will conduct implementation research aligning Gavi's IRMMA framework for generating evidence-based interventions for reducing ZD and UI children. This will be accomplished by working in conjunction with the Government, local academic institutions and civil society organizations (CSOs) of the country. Objectives: The objectives of the research are to: 1. Understand the effective methods for identifying ZD children and missed communities 2. Identify the key barriers and enabling factors at different levels (policy down to community, and including supply, demand, and gender-related barriers) to identify ZD children 3. Develop and test appropriate approaches to reach ZD children and missed communities and to bring them into the health system in order to achieve full immunization 4. Identify the key barriers and enabling factors at each level (down to community) to reach ZD children and to bring them into the health system through full immunization Methods: This quasi-experimental pre-post design study will be conducted in six areas selected via rapid assessment that was conducted by Bangladesh country learning hub team. Each of the selected area will have a comparison area. The duration of the IR will be 18 months starting from September 2023. We will conduct the implementation research to test a set of interventions targeted to six types of areas already known to have higher levels of ZD. Mixed methods approach including baseline and endline household surveys and qualitative methods will be used for evaluation of effectiveness of the interventions. The baseline and endline survey data in the intervention and comparison areas will be analysed for comparison and estimation of difference-in-difference in ZD level. Multivariate analyses will be carried out to estimate the net effect of the intervention on zero-dose level, controlling for all confounders. Outcome measures/variables: The primary outcomes are the change(s) in prevalence of "ZD and under-immunized" children from baseline to endline periods.