This study will evaluate the safety, infectivity, and immunogenicity of two doses of the HPIV3/ΔHNF/EbovZ GP vaccine candidate when administered intranasally in healthy adults.~Participants will be enrolled sequentially in two cohorts. Participants in Cohort 1 will be randomly assigned to receive two doses of either 10^6.0 PFU/mL of HPIV3/ΔHNF/EbovZ-GP vaccine or placebo. The first dose will be given on Day 0 and the second dose will be given 4-8 weeks later. Participants in Cohort 2 will be randomly assigned to receive two doses of either 10^7.0 PFU/mL of HPIV3/ΔHNF/EbovZ-GP vaccine or placebo on Days 0 and 28.~Participants will be admitted to the inpatient unit 2 days prior to receiving their first dose of the vaccine or placebo. While in the inpatient unit, study procedures will include physical examinations, nasal washes, and blood collection. Participants will be discharged from the inpatient unit on Day 8 or thereafter once two consecutive rRT-PCR assay results are below the pre-determined threshold. An additional study visit will occur on Day 14.~On Day 26 (+28), participants will be readmitted to the inpatient unit, and will receive their second dose of the vaccine or placebo on Day 28 (+28). Participants will undergo the same study procedures that occurred during the first inpatient stay, and will be discharged 7 days after the second dose, or once the subject is without respiratory symptoms and rRT-PCR assay is below the pre-determined threshold (around Day 35). Additional study visits will occur on Days 42 ± 3, 56 ± 5, 84 ± 5, 112 ± 7, 180 ± 14, 270 ± 14, and 360 ± 30.
The purpose of this study is to evaluate the safety, infectivity, and immunogenicity of two doses of the HPIV3/ΔHNF/EbovZ GP vaccine candidate when administered intranasally in healthy adults.