Phase I Study of West Nile Virus Vaccine

Study Design: This is a Phase I open-label study to evaluate safety, tolerability, and immunogenicity of a recombinant DNA vaccine, VRC-WNVDNA020-00-VP. The hypothesis is that this regimen will be safe for human administration and elicit a higher titer of neutralizing antibody response than a prior WNV DNA vaccine. The primary objectives are to evaluate the safety and tolerability in humans of the investigational vaccine in healthy young adults and in healthy older adults. Secondary and exploratory objectives are related to the immunogenicity of the study vaccine. Product Description: VRC-WNVDNA020-00-VP is composed of a single closed-circular DNA plasmid that encodes the WNV viral protein precursor transmembrane (prM) and envelope (E) with a CMV/R promoter. Vaccine vials will be supplied at 4 mg/mL. Each DNA vaccination will be 1 mL of vaccine administered intramuscularly (IM) in the deltoid muscle using the Biojector 2000 Needle-Free Injection Management System (Biojector). Subjects: A total of 30 healthy adults will be enrolled in two groups: Group 1 will be comprised of 15 healthy adults 18 to 50 years old and Group 2 will be comprised of 15 healthy adults 51 to 65 years old. Study Plan: All subjects will receive 3 injections on the schedule shown in the schema. The protocol requires nine clinic visits and three telephone follow-up contacts. Study Duration: 32 weeks of clinical follow up for each participant. A long-term follow-up contact at Week 52 may include interim medical history and research blood draw; or subject may opt for the long-term contact to occur by telephone, e-mail or mail for the interim medical history only. Study Endpoints: The primary endpoint is safety and tolerability of the regimen. The secondary immunogenicity endpoints are WNV neutralizing antibody, WNV specific antibody as measured by ELISA, WNV-specific T cell responses measured by intracellular cytokine staining (ICS) assay and ELISPOT. Other immunogenicity assays through Week 32 may also be completed as exploratory evaluations, as well as from the Week 52 blood samples if collected.