Safety and Immunogenicity of a Zika Virus DNA Vaccine, VRC-ZKADNA085-00-VP, in Healthy Adults

Study Design: 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. Product Description: 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. Subjects: Healthy adults 18 to 35 years of age. Study Plan: Subjects will be enrolled at up to 3 study sites, randomized equally into the 4 study groups, and will receive 2-3 vaccinations. The protocol requires up to 18 scheduled clinic visits and a telephone follow-up contact after each study injection. Solicited reactogenicity will be evaluated using a 7-day diary card. Assessment of vaccine safety will include clinical observation and monitoring of hematological and chemical parameters at clinical visits through the 44 weeks on the study. -VRC 319 Study Schema * Group:1; Subjects\*: 20; Day 0; Week 8; * Group:2; Subjects\*: 20; Day 0; Week 12; * Group:3; Subjects\*: 20; Day 0; Week 4; Week 8; * Group:4; Subjects\*: 20; Day 0; Week 4; Week 20; * TOTAL; Subjects\*: 80 * Up to 120 total enrollments are permitted if additional subjects are needed for assessment of safety and immune responses. Study Duration: Subjects will be evaluated for safety and immune responses throughout the study for 44 weeks following the first vaccine administration and for durability of immune responses at two additional long term follow-up visits at 18 and 24 months.