National immunization research agenda setting in a lower-middle-income country: a stakeholder- informed modified Delphi study in Honduras

Background Strengthening immunization programs in low- and middle-income countries requires context-specific evidence to inform policy and programmatic decisions. Research efforts often remain fragmented and poorly aligned with national priorities. A coordinated, stakeholder-informed research agenda helps ensure that evidence generation addresses the gaps most relevant to program performance. This study aimed to define national research priorities for immunization in Honduras through a structured multi-stakeholder consensus process. Methods A modified Delphi study was conducted virtually and asynchronously between February and April 2026. A multisectoral panel from the Ministry of Health, international health organizations, clinical services, and academia evaluated a preliminary list of 24 research topics across six thematic domains over three rounds. In round one, participants indicated whether each topic was relevant to the national context and proposed additional topics through open-ended questions analyzed thematically. In round two, participants rated the consolidated research lines on a five-point Likert scale for national public health relevance and the applicability of the expected evidence to decision-making; lines needed at least 70% of responses in the two highest categories on both dimensions to advance. In round three, panelists reviewed the aggregated round two results and selected the eight highest-priority lines among those that had reached consensus, ranked by selection frequency. Results Twenty-six experts completed round one and constituted the panel; 24 (92.3%) and 25 (96.2%) completed rounds two and three. Round one produced 18 revised research lines from the initial 24 topics, of which 16 (88.9%) reached consensus in round two. The eight lines prioritized in round three addressed evaluation of immunization information systems, barriers to and facilitators of vaccine acceptability, missed opportunities for vaccination, access barriers among vulnerable populations, sociocultural and structural determinants of schedule completion, risk communication strategies, health worker competencies, and surveillance of vaccine-preventable diseases and vaccine effectiveness. Conclusions This study produced the first stakeholder-consensus national research agenda for immunization in Honduras. The prioritized lines center on strengthening program implementation rather than on vaccine technology development, offering a context-specific roadmap for research investment in a lower-middle-income setting.