This is a Phase I/Ib, randomized, multicenter clinical study to evaluate the safety, tolerability, and immunogenicity of four vaccination regimens against Zika virus (ZIKV) disease. Vaccination regimens with the VRC-ZKADNA085-00-VP (ZIKV DNA) vaccine administered on Day 0 and Week 8 (Group 1); on Day 0 and Week 12 (Group 2); on Day 0, Weeks 4 and 8 (Group 3); and on Day 0, Weeks 4 and 20 (Group 4) will be tested. The primary hypothesis is that the ZIKV DNA vaccine will be safe and well tolerated in healthy adults. A secondary hypothesis is that all vaccine regimens will elicit a ZIKV-specific immune response. The primary objectives are to evaluate the safety and tolerability of the investigational vaccine regimens in healthy adults. Secondary objectives are related to the immunogenicity of the vaccination regimens.
The investigational VRC-ZKADNA085-00-VP vaccine was developed by the Vaccine Research Center (VRC), NIAID, and is composed of a single closed-circular DNA plasmid that encodes the wild type precursor transmembrane M (prM) and envelope (E) proteins from the H/PF/2013 strain of ZIKV. Vaccine is supplied in single dose vials at a concentration of 4 mg/mL. ZIKV DNA vaccine dose will be 4 mg administered as an intramuscular (IM) injection in the deltoid muscle.