Barriers to dengue vaccine uptake in international travelers: a mixed-methods study

Background Dengue poses a growing threat to international travelers, yet vaccine uptake remains limited due to inconsistent guidelines and psychological barriers. This study provides barriers and determinants of hesitancy, which may guide strategies once global dengue vaccination guidelines for travelers are established.Research design and methods We conducted an explanatory sequential mixed-methods study from May 2024 to March 2025 in Bangkok, Thailand, assessing vaccine hesitancy among 429 international travelers using the 5C model and thematic analysis of interviews.Results The prevalence of dengue vaccine hesitancy was higher than previous literature. Dengue vaccine acceptance was 36.8%, with non-religious affiliation (adjusted odds ratio [aOR]: 4.89; 95% CI: 2.55–9.38), higher confidence, and lower perceived constraints significantly associated with acceptance. Non-acceptors reported significantly higher levels of complacency and constraints, and lower collective responsibility scores (all p < 0.001). Travelers often underestimated dengue risk and cited logistical challenges and vaccine accessibility as barriers. Trust in healthcare providers, especially from endemic regions, influenced decisions, while collective responsibility was less relevant.Conclusions High dengue vaccine hesitancy highlights the need for healthcare providers to enhance vaccine confidence through evidence-based counseling and address complacency by correcting risk misconception. Improving vaccine accessibility and aligning schedules with travel plans may reduce constraints and vaccine messaging may be more effective by prioritizing individual-level benefit to maximize impact once global guidelines are established.Clinical trial registration The study was registered with the Clinical Trials.gov (Clinical trial.gov NCT06418854).