Improving primary care vaccination rates in underserved and medically high-risk populations: A rapid review of strategies used in Australia and Aotearoa New Zealand

BACKGROUND: Despite excellent evidence for the effectiveness of vaccines and their inclusion within multiple clinical guidelines, vaccination coverage remains sub-optimal and inequitable in countries around the world, including in Australia and Aotearoa New Zealand. Interventions in primary care, and involving primary care providers, can be especially helpful to improve vaccination coverage. METHODS: We conducted a rapid review of research published between 2015 and 2024 that described either interventions, or barriers and enablers, to improving vaccination coverage for medically high-risk and underserved populations. Studies needed to be conducted in primary care in Australia or Aotearoa New Zealand. First, thematic analysis was used to describe barriers and enablers. Then, the content and outcomes of the included interventions were synthesised. Finally, barriers and enablers were mapped against the intervention strategies, to identify gaps between these factors. RESULTS: Of the 42 included articles, 37 identified barriers and enablers, 11 described an intervention to improve vaccination coverage, and six did both. Barriers and enablers were identified at the consumer, practitioner and practice, and healthcare system level. Consumer-level factors included mistrust and hesitancy (barriers), and high perceived benefits of vaccination (enabler). Practice-level factors included competing demands (barrier), and positive attitudes towards population health interventions (enablers). Healthcare system-level factors included a lack of culturally informed services and issues with digital health systems (barriers), and policy-level supports for the development of co-designed, culturally informed, and equitable vaccination care pathways (enablers). These multi-level factors were rarely comprehensively addressed in interventions aiming to improve coverage. Instead, effective interventions tended to be narrower in scope, and included personalised vaccination calendars, SMS-reminder programs, and structured health assessments. CONCLUSIONS: The modest, but positive impacts of successful interventions may be improved using multi-level interventions that are tailored to target contexts and populations, which should be the focus of future work.