Eligibility Criteria for Yellow Fever Vaccine

Healthy adults aged 18–60 years were eligible for enrollment in the study. Exclusion criteria included fever (≥38°C) within three days of vaccination; known hypersensitivity or allergy to the vaccine or components; contraindications to YF-17D vaccine receipt; any serious chronic or progressive disease; altered immune function; body mass index ≥ 35kg/m²; pregnancy or breastfeeding; participation in another clinical trial within 30 days; receipt of vaccines prior to enrollment (14 days for inactivated, 28 days for live vaccines); previous vaccination against any flavivirus or tick-borne encephalitis; current or previous flavivirus infection and ≥1 year living in a dengue-endemic area.