Dengue viruses account for more than 50 million cases of dengue fever and one half million cases annually of dengue hemorrhagic fever/shock syndrome. Dengue virus infections can cause illness ranging from mild, self-limited febrile illness to life threatening diseases. The goal of dengue vaccine development is to induce a long-lived antibody response against all four dengue serotypes. The rDEN1delta30 vaccine is a live attenuated dengue virus vaccine that may be protective against dengue serotype 1 (DEN1). The purpose of this study is to evaluate the safety, reactogenicity, and immunogenicity of a 2-dose regimen of rDEN1delta30 dengue virus vaccine. The regimen will differ in when the second booster shot of the vaccine is given.~This study will last 162 days (about 23 weeks) for those participants in Cohort 1, and 222 days (about 32 weeks) for those in Cohort 2. Participants in Cohort 1 will be randomly assigned to receive rDEN1delta30 vaccine or placebo on Study Day 0 and Study Day 120. Participants in Cohort 2 will be randomly assigned to receive rDEN1delta30 vaccine or placebo on Study Day 0 and Study Day 180.~There will be a total of 25 visits for each cohort. For both cohorts, the first and second vaccination days will include a physical exam and blood and urine collection, vital signs measurements, and receipt of the vaccine. A 30 minute observation period will follow vaccination. Participants will take their temperature at home three times a day for the first 16 days and report it in a diary. At all other study visits, vital signs measurements, a physical exam, and blood and/or urine collection will occur. At selected study visits, participants will turn in their diary cards.~Some participants may be asked to join an optional skin biopsy substudy.
Dengue fever, caused by dengue viruses, is a major health problem in tropical and subtropical regions of the world. The purpose of this study is to evaluate the safety of and immune response to a 2-dose regimen of a new monovalent dengue virus vaccine. This study will test the dengue virus vaccine DEN1delta30 in healthy adults.