Shared evidence, different recommendations: a comparative analysis of Qdenga (TAK-003) dengue vaccine guidance for travellers across countries

Abstract Background Dengue is an increasingly important cause of illness in travellers, and Qdenga (TAK-003) is the first dengue vaccine incorporated into guidance for travellers in multiple countries. However, clinicians and travellers may encounter differing recommendations across jurisdictions. This study compared guidance on the use of Qdenga in travellers across countries. Methods We conducted a comparative analysis of national guidance on Qdenga use for travellers across countries, using survey data and structured review of publicly available recommendations. Guidance was synthesised according to dengue immune status and mapped across recurring decision domains. Results Survey responses were obtained from 18 advisory bodies across 17 countries between March and April 2026, including twelve non-endemic countries where Qdenga was licensed and guidance published. Guidance was generally more restrictive than regulatory authorisation. While there was broad agreement in recommending vaccination for travellers with laboratory-confirmed prior dengue infection, recommendations for those without documented infection varied widely. All advisory bodies considered destination-specific dengue risk but differed in whether and how they used travel duration, repeated or cumulative exposure, traveller characteristics and host susceptibility factors to determine vaccine eligibility. Some recommendations restricted vaccination to travellers with prior dengue infection, whereas others extended eligibility to selected travellers without documented prior infection or recommended vaccination irrespective of serostatus based on exposure risk. Approaches also differed in assessment of prior dengue infection and whether completion of the two-dose series before travel was required. Conclusions Variation in Qdenga guidance reflects differences in how advisory bodies interpret shared evidence and manage uncertainty arising from data gaps and differences between trial populations and travellers. Additional data on vaccine effectiveness and clinical outcomes among seronegative travellers and older adults may help reduce uncertainty and support greater alignment of future recommendations. Regardless, transparency and shared clinical decision-making remain essential when discussing dengue vaccination with travellers.