Dengue infection is a leading cause of illness and death in the tropics and subtropics. The infection is caused by any one of four types of the dengue virus. This study will evaluate the safety of and immunogenicity to a vaccine (called TV003) against all four types of the dengue virus in healthy adults, adolescents, and children aged 12 months to 50 years in Thailand.~Participants will be enrolled sequentially in four age groups (adults, adolescents, children, and young children), and researchers will evaluate safety data before enrolling each subsequent cohort. Each participant will be in the study for approximately 12 months.~At study entry (Day 0), participants will be randomly assigned to receive either the TV003 vaccine or a placebo vaccine for TV003. All participants will receive two doses of TV003 or placebo-the first dose at study entry (Day 0) and the second dose 6 months later on Day 180. Additional study visits will occur on Days 6, 9, 12, 15, 28, 56, 72, 186, 189, 192, 195, 208, 236, 252, and 360.~All study visits will include a medical history review and a physical exam. Select study visits will also include blood collection and a urine pregnancy test for participants of childbearing potential.~At the vaccination study visits, participants will remain in the clinic for approximately 30 minutes after each vaccination for observation and monitoring. For 20 days after each vaccination, participants will take their temperatures and record any symptoms. Throughout the entire study period, study researchers will monitor participants for suspected dengue infection.
The purpose of this study is to evaluate the safety of and immune response to two doses of a dengue vaccine (TV003) given 6 months apart to healthy adults, adolescents, and children in Thailand.