Abstract
The COVID-19 pandemic coupled with recent upheavals in global trade and development assistance funding has disrupted routine immunization programmes and diverted health systems from the targets set in the Immunization Agenda 2030. Regulatory systems are often underappreciated or misunderstood but in fact play a critical role in enabling innovation and facilitating timely access to vaccines for sustained immunization, thereby building vaccine confidence and health system resilience. Regulation is the constant denominator throughout the vaccine life cycle, shaping the pathway from early research and development to approval and market entry and ultimately to equitable distribution and sustained safe use. This paper examines the role of regulation and proposes that regulation be reframed as a function of health system resilience and a structural determinant of immunization sustainability. We synthesize evidence across the vaccine regulatory life cycle, examining innovation facilitation, regional cooperation, public health strengthening and describe the roles of regulation in building health system resilience, namely driving sustainable vaccine access, enabling innovation, supporting regional collaboration and strengthening social acceptance. Without this shift in perspective, regulatory systems strengthening risks being underfunded, reactive, and fragmented; this will perpetuate inequities in vaccine access and undermine the sustainability of immunization programmes.