Evaluation of Two Zika Viruses for Use in Controlled Human Infection Models (CHIM)

Inclusion Criteria: * Adult ZIKV and DENV-naïve male and non-pregnant females 18 - 40 years of age, inclusive. * Good general health as determined by physical examination, laboratory screening, and review of medical history. * Available for the duration of the study, approximately 26 weeks post-inoculation. * Must be able to complete the informed consent process and comprehension assessment independently and without assistance. * Willingness to participate in the study as evidenced by signing the informed consent document. * Willingness to reside in the inpatient unit for 9 days (or longer for safety if necessary) following receipt of ZIKV or placebo. * Male subjects: Willingness to use barrier contraception during cervico-vaginal, anal, and oral intercourse through study day 90 (in accordance with CDC guidance). * Female subjects: Willingness to use barrier contraception during cervico-vaginal, anal, and oral intercourse through study day 56 (in accordance with CDC guidance). * Female subjects of childbearing potential must be willing to use effective contraception while at risk of Zika infection. CDC guidelines for the use of effective contraception of 8 weeks post-infection will be followed; time of infection is defined as inoculation with challenge virus. Reliable methods of contraception include: hormonal birth control\* (implantable, hormonal patch, hormonal vaginal ring, oral contraception, Depo-Provera injection, etc.), surgical sterilization (hysterectomy, tubal lig…