Safety, and Efficacy Study of ShigETEC, a Live, Attenuated, Oral Combination Vaccine to Prevent Shigella and ETEC Disease Delivered to Healthy Adults Ages 18 to 50 Years Old
brief summary
The purpose of this study is to evaluate the efficacy of the oral, live, attenuated ShigETEC vaccine against challenge with S. flexneri 2457T. In Stage 1 of this study, ShigETEC vaccine or placebo will be administered orally to healthy participants at a dose of 5x10\^10 CFU. This dose was tested in a Phase 1 trial and found to be safe when given 4 times with an interval of 3 days between each dose. The efficacy of ShigETEC vaccination will be evaluated in Stage 2 of this study, when participants will be challenged with S. flexneri 2457T. The study population will be healthy adult participants in the age of 18-50 years (inclusive), which are clearly defined in the study protocol.
detailed description
This is a two-stage, randomized, double blind, placebo-controlled Phase 2b study in healthy participants conducted at a single site.
The study will be conducted in two Stages (Stage 1 and Stage 2) and two arms in Stage 1 (Arm 1 and Arm 2).
Stage 1 Stage 1 will be conducted in an outpatient setting and includes the vaccination with the investigational product, ShigETEC, a live, attenuated, oral vaccine (Arm 1) and placebo (Arm 2) and subsequent follow-up.
Stage 2 Stage 2 will include an infectious challenge of selected Stage 1 participants in an inpatient setting (CHIM: Controlled Human Infection Model) in which participants will receive 1 oral dose of Shigella flexneri 2a 2457T and be followed closely for the signs and symptoms of shigellosis.
Stage 2 will start 21 (+5) days after the last dose of vaccine or placebo.
official title
A Two-stage, Phase 2b, Randomized, Double-blind, Placebo-controlled Safety, and Efficacy Study of ShigETEC, a Live, Attenuated, Oral Combination Vaccine to Prevent Shigella and ETEC Disease Delivered to Healthy Adults Ages 18 to 50 Years Old