Dengue viruses are a major health concern, particularly in the tropical and subtropical regions of the world. The World Health Organization (WHO) has made the development of a dengue vaccine a top priority. There are four types of dengue viruses (DEN1, DEN2, DEN3, and DEN4), each of which can cause various illnesses, including dengue fever, or the more severe disease, dengue hemorrhagic fever/shock syndrome (DHF/DSS). This study will evaluate the safety and immune response to two doses of a dengue virus vaccine (TV003) when administered 12 months apart in healthy adults. The study will also evaluate whether the candidate vaccine may protect against all four types of dengue viruses.~Participants will be randomly assigned to receive the TV003 study vaccine or placebo vaccine. At study entry, participants will undergo a blood collection and physical examination, and female participants will take a pregnancy test. Participants will then receive an injection of their assigned vaccine. They will take their temperature three times a day for 16 days after each vaccination and record the results on a diary card, which research staff will review during participants' study visits. Additional study visits will occur on Days 3, 10, 14, 21, 28, 56, 90, 180, 270, and 330. All study visits will include blood collection and a physical examination; select visits will include a pregnancy test for female participants. At a study visit on Day 360, all participants will receive an injection of the same vaccine they received at study entry. Additional study visits will occur on Days 363, 370, 374, 381, 388, 416, 450, and 540, and will include the same study procedures as previously performed.
Dengue viruses can cause dengue fever and other more severe forms of disease. This study will evaluate the safety and immune response to two doses of a dengue virus vaccine given 12 months apart in healthy adults.