EFFECTIVENESS OF INTERVENTIONS TO INCREASE VACCINE UPTAKE:A COMPONENT NETWORK META-ANALYSIS

Objective<br/>To identify the effective components of vaccine uptake interventions and explore variations by population group and context.<br/>Design <br/>Data from a systematic review of randomised controlled trials in high and upper-middle income countries, targeting vaccine recipients (or their caregivers) to increase uptake of UK-scheduled vaccinations were analysed. Using a bespoke coding framework co-developed with stakeholders, key content and delivery features were identified. Bayesian component-level meta-regression estimated relative effects as ratios of odds ratios (RORs) with credible intervals (CrI).<br/>Results<br/>237 studies with 570 intervention arms and 4,361,717 participants (40%, N = 1,744,686 male) were included. 110 studies were at low risk of bias, 96 some concerns, and 31 high risk. For children, there was evidence of beneficial effects of payment to cover costs (ROR:3.01, 95%CrI:1.49 to 6.06); decision aids (ROR:2.73, 95%CrI:1.14 to 7.06); and some evidence for extended opportunities (ROR:1.37, 95%CrI: 0.98 to 1.95); and social factors (ROR:1.27, 95%CrI:0.99 to 1.65). For adolescents/young adults, there were beneficial effects of personal delivery formats (ROR:2.13, 95%CrI:1.09 to 4.40); delivery by community members alongside healthcare professionals (ROR:6.42, 95%CrI:1.94 to 25.62); and social factors (ROR:2.62, 95%CrI:1.45 to 5.04); and negative effects of decision aids (ROR:0.43, 95%CrI:0.18 to 0.98), and human over non-human interaction (ROR:0.47, 95%CrI:0.21 to 1.02). For adults, human interaction (ROR:1.86, 95%CrI:1.42 to 2.45); extended opportunities (ROR:1.63, 95%CrI:1.35 to 2.00); appointment scheduling help (ROR:1.38, 95%CrI:1.06 to 1.78); payments to cover costs (ROR:1.47, 95%CrI:1.03 to 2.16); and motivational interviewing (ROR:1.79, 95%CrI:1.21 to 2.64) had positive effects, and there was some evidence for financial incentives (ROR:1.15, 95%CrI:0.99 to 1.35) and vaccine safety/efficacy information (ROR:1.15, 95%CrI: 0.99 to 1.32). There was also evidence of a negative effect of non-human interaction compared to no interaction (ROR:0.72, 95%CrI:0.57 to 0.92). Subgroup analyses showed variation by time period and for underserved populations.<br/>Conclusion<br/>These findings have significant implications for designing, optimising, and implementing targeted interventions to increase vaccine uptake, highlighting which components are most effective across different populations and contexts. Consideration of the economic data on interventions will further support resource-informed decision-making.<br/>