Determinants and mitigation strategies of vaccine hesitancy toward routine immunisations recommended for older adults: a systematic review.

BACKGROUND: Vaccine hesitancy among older adults has increasingly raised public concern and warrants global actions in the post-COVID-19 era. This systematic review aimed to synthesise determinants of vaccine hesitancy and related mitigation strategies toward routine vaccinations recommended for older adults (influenza, pneumococcal and shingles vaccines), which is important for promoting healthy ageing and fighting against infectious diseases during both pandemic and non-pandemic periods. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, a systematic literature search was conducted between November 2024 and June 2025 across Web of Science, PubMed and MEDLINE. The data were analysed by narrative synthesis guided by two theoretical frameworks. RESULTS: A total of 72 studies were included. Most of them were conducted in developed countries, with a surge since the COVID-19 pandemic. Determinants of vaccine hesitancy were summarised from 49 studies into 3 levels, 8 themes and 24 sub-themes: individual level (sociodemographics, personal perceptions, previous experiences), group and social level (interpersonal influence, community influence, media/cultural influence) and practical issues level (willingness to pay, convenience of access). The intervention strategies were categorised from 23 studies into five types, including dialogue-based intervention, reminder/recall-based intervention, incentive-based intervention, passive intervention and multi-component intervention. Notably, this review identified a lack of conceptual clarity in distinguishing vaccine hesitancy from actual vaccination behaviours and a shortage of comprehensive interventions tailored to older adults. CONCLUSION: Vaccine hesitancy toward routine immunisations among older adults is driven by multilayer determinants, underscoring the need for comprehensive, theory-informed and tailored interventions that address the diverse determinants.