Safety Study of Hepatitis E Vaccine (HEV239)

This is a Phase I double-blind, randomized, placebo controlled trial (1:4 ratio of placebo to vaccine) of Hepatitis E virus vaccine containing a 239 amino acid subfragment of Hecolin(R) (HEV-239) in 25 US males and non-pregnant females ages 18 - 45 (inclusive) to assess the safety, reactogenicity, and immunogenicity of HEV-239. Subjects will receive 3 doses of study product on Days 1, 29, and 180. Subjects will remain in the study for up to 13 months (including screening). The study duration will be approximately 15 months. Subjects will be observed for 30 minutes after vaccination. The occurrence of solicited injection site and systemic reactogenicity events will be measured from the time of study vaccination through Day 8 after each vaccination. These will be ascertained through use of an electronic memory (e-memory) aid, a telephone call on day 4 after each dose of vaccine, a Day 8 clinic visit, and potentially at the Day 15 clinic visit after each dose of vaccine. Unsolicited adverse events will be collected from vaccination through Day 29 after each vaccination. Serious adverse events will be collected from the time of the first study vaccination through the last study visit (Day 360). The study includes multiple phlebotomy time points for immunogenicity and blood collection for future use at visit 1 and Days 8, 15, and 29 after each vaccination. The durability of the immune response and future use collection will be assessed at 5 months after the first boost (Day 180) and at 6 months after the second boost (Day 360). The primary objectives of the study are to; 1) Assess the safety and reactogenicity of HEV-239 following delivery of each vaccine dose; and 2) Assess the number of subjects with \> / = 4 fold rise in Hepatitis E virus (HEV) immunoglobulin G (IgG) at any time after vaccination. The secondary objectives are to; 1) Assess the number of subjects with HEV immunoglobulin M (IgM) seroconversion at any time after vaccination; 2) Assess the number of subjects with HEV IgG seroconversion at any time after vaccination; and 3) Assess the HEV IgG geometric mean concentrations (GMCs) at any time after vaccination.