Safety and Immunogenicity of the Live Attenuated Zika Vaccine rZIKV/D4Δ30-713 in Flavivirus-naïve Adults

Fifty-six healthy volunteers will be enrolled over 2 sequential cohorts: Cohort 1: n=28, volunteers will be randomly assigned to a single dose of either vaccine (10\^3 PFU, n=20) or placebo (n=8). Cohort 1 will be enrolled and evaluated first. If the vaccine is not found to induce seroconversion to ZIKV in \> 80% of subjects inoculated with 10-\^3 PFU of the vaccine, a second cohort of volunteers will be enrolled and will be inoculated with 10\^4 PFU of vaccine (or placebo). Cohort 2: n=28, volunteers will be randomly assigned to a single dose of either vaccine (10\^4 PFU, n=20) or placebo (n=8). All volunteers will be followed on an outpatient basis for 6 months following vaccination (13 follow up visits over 180 days). Follow up visits will include clinical assessments as well as sample collection for evaluation of viremia and seroconversion. Sample collection will include blood, urine, saliva, nasopharyngeal or midturbinate swab, vaginal secretion or semen collection on specified visit days throughout the 180 day follow up period.