Exploring the delivery of adult vaccination outside of primary care settings: A mixed methods scoping review

Background: There are several identified barriers to immunisation delivery and uptake in adults, including governance issues, provider limitations, and patient access. While primary care settings have traditionally been responsible for vaccine delivery, there is a growing need to look to other settings to expand the equitable uptake of vaccinations in adults. Objectives: This scoping review aims to identify and explore the role of non-primary care settings in delivering adult vaccinations, operational barriers and facilitators to immunisation delivery in these settings, and interventions delivered to improve uptake. Methods: This scoping review was conducted following the Joanna Briggs Institute (JBI) guidance for scoping reviews and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Peer-reviewed studies published from 01/01/2010 to 31/12/2022 that focused on the delivery of influenza, COVID-19, pneumococcal and herpes zoster vaccines in adult populations outside of primary care settings were included. Studies were also included if they explored barriers and facilitators to delivery, and interventions to improve uptake. Results: 75 studies were identified for inclusion. Most were quasi-experimental studies, and 58/75 were from the US. Studies were most frequently conducted in in-patient settings, outpatient clinics, nursing homes, and workplaces. Operational planning and logistics, and provider-level issues, such as poor documentation and workflow interruption were commonly identified barriers to delivery. Government funding, continuity of care, and patient convenience were frequently reported facilitators. Interventions shown to improve uptake were operational planning and clinical improvement systems (Plan-Do-Study-Act [PDSA] cycles), provider education and reminders, on-site vaccination, patient education, and financial incentives. Conclusions: Mapping of the evidence indicates that adult immunisation delivery may be achievable across tertiary and secondary care settings, as well as non-clinical settings, such as workplaces. There are several identified barriers to delivery, predominantly at the provider-level in tertiary-care settings. Intervention such as operational planning, clinical reminders, and on-site vaccination, may facilitate uptake.