Identifying characteristics that enable resilient immunisation programmes: a scoping review.

OBJECTIVES: The COVID-19 pandemic highlighted the fragility of immunisation programmes and resulted in a significant reduction in vaccination rates, with increasing vaccine-preventable disease outbreaks consequently reported. These vulnerabilities underscore the importance of resilient immunisation programmes to ensure optimal performance during crises. To date, a framework for assessing immunisation programme resilience does not exist. We conducted a scoping review of immunisation programmes during times of crisis to identify factors that characterise resilient immunisation programmes, which may inform an Immunisation Programme Resilience Tool. DESIGN: Scoping review design followed the Arksey and O'Malley framework, and manuscript reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews guidelines. DATA SOURCES: CINAHL, CENTRAL, Embase, Google Scholar, MEDLINE, PsycINFO and Web of Science and databases were searched between 1 January 2011 and 2 September 2023. Citation searching of identified studies was also performed. ELIGIBILITY CRITERIA: We included primary empirical peer-reviewed studies that discussed the resilience of immunisation programme to crises, shocks or disruptions. DATA EXTRACTION AND SYNTHESIS: Two independent reviewers screened records and performed data extraction. We extracted data on study location and design, crisis description, and resilience characteristics discussed, and identified evidence gaps in the literature. Findings were synthesised using tabulation and an evidence gap map. RESULTS: Thirty-seven studies met the eligibility criteria. These studies captured research conducted across six continents, with most concentrated in Africa, Asia and Europe. One study had a randomised controlled trial design, while 36 studies had observational designs (15 analytical and 21 descriptive). We identified five characteristics of resilient immunisation programmes drawing on the Health System Resilience Index (Integration, Awareness, Resource Availability and Access, Adaptiveness and Self-regulation) and several evidence gaps in the literature. CONCLUSIONS: To our knowledge, no immunisation programme resilience tool exists. We identified factors from the Health System Resilience Index coupled with factors identified through primary empirical evidence, which may inform development of an immunisation programme resilience tool.