Japanese encephalitis vaccine solution for injection 1ml vials

ImportanceJapanese encephalitis (JE) is a mosquito-borne disease with low infection risk but high consequences. Low uptake of JE vaccines among travelers persists despite effective vaccines. Tools that improve decision quality may help address this gap.ObjectiveTo evaluate whether a web-based JE vaccine decision aid (JEVaDA) improves decision-making and vaccine uptake among Australian travelers compared with an online government JE resource.Design, setting, and participantsThis parallel-group, single-blind randomized clinical trial was conducted online across Australia from November 6, 2024, to July 14, 2025. Adults (aged ≥18 years) planning travel to a JE-endemic country within 6 months were recruited via a research panel.InterventionsParticipants were randomized 1:1 to the JEVaDA intervention, developed to International Patient Decision Aid Standards, or an online government JE resource (the active comparator).Main outcomes and measuresThe primary outcome was postintervention decisional conflict, measured using the Decisional Conflict Scale (DCS) (scores range from 0 to 100, with higher scores indicating greater conflict). Secondary outcomes included change in JE knowledge, intention to vaccinate, and self-reported vaccine uptake. Analyses used regression models adjusted for baseline values, age, and gender.ResultsOf the 1879 individuals screened, 814 were randomized and 769 completed preintervention and postintervention assessments (modified intention-to-treat population: 373 in the intervention group and 396 in the comparator group). Their mean (SD) age was 44.7 (15.2) years; 394 (51.2%) identified as women. The intervention and comparator groups showed significant reductions in decisional conflict (mean DCS score change, -10.94 [95% CI, -12.81 to -9.07] vs -11.58 [-13.24 to -9.91] points, respectively; both P Conclusions and relevanceIn this randomized clinical trial, the web-based JEVaDA was not associated with a further reduction in decisional conflict compared with an active comparator but was associated with higher vaccine uptake. These findings suggest that decision aids can support informed, values-congruent choices in complex, preference-sensitive health decisions such as travel vaccination and beyond.Trial registrationanzctr.org.au Identifier: ACTRN12624001176550.

Abstract licence: CC BY