This study will last 180 days. There will be three cohorts in this dose de-escalation study. Participants in Cohort 1 will be randomly assigned to receive the highest dose of rDEN4delta30-200,201 or placebo at study entry. Cohort 2 will begin only after safety review of all participants in Cohort 1. Participants in Cohort 2 will receive a lower dose of rDEN4delta30-200,201 or placebo. Cohort 3 will begin only after safety review of all participants in Cohort 2. Participants in Cohort 3 will receive the lowest dose of rDEN4delta30-200,201 or placebo.