Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: A Phase 1, Randomized, Observer Blinded, Placebo Controlled, Single Center, Dose Escalation Study to Evaluate the Safety and Immunogenicity of 3 Vaccinations With Shigella
Brief Summary:
This Phase 1 clinical trial is aimed to evaluate the safety and immunogenicity of 3 doses of 5 sequentially escalating dosages of a candidate vaccine against Shigella sonnei (1790GAHB vaccine) administered by intramuscular route in healthy adults (18 to 45 years of age at enrollment). The safety profile of the 1790GAHB vaccine is evaluated in comparison to that of placebo (GAHB-Placebo), constituted by an aluminum hydroxide suspension having the same concentration as study vaccine formulations. A total of 50 eligible subjects will be assigned to one of five sequential cohorts of 10 subjects each.
Within each cohort, in an observer-blind fashion, subjects will be randomized to receive three vaccinations, four weeks apart, of either 1790GAHB vaccine (at five antigen concentrations) or GAHB placebo. A Data Safety Monitoring Board will be in place to receive a summary of all safety data obtained during one week follow-up post-first vaccination with the lower dose. Based on evaluation of the safety data, the Data Safety Monitoring Board will make a recommendation, as to whether the next cohort should be vaccinated with higher antigen concentration or not.
Expected duration of the study for an individual subject is 9 months. Each subject will be followed-up for 6 months after the 3rd vaccination.