Phase 2 Shigella Vaccine and Challenge
Public ClinicalTrials.gov record NCT04242264. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
A Double-Blind Placebo Controlled Randomized Phase 2 Trial to Evaluate the Safety, Reactogenicity and Immunogenicity of a Live-Attenuated Shigella Sonnei Vaccine, WRSs2 and Determine Its Efficacy in a Challenge Model of S. Sonnei 53G in Healthy Adults
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This is a trial to evaluate the safety, reactogenicity, immunogenicity and efficacy of a 10\^6 cfu dose of an oral live-attenuated S. sonnei vaccine candidate, WRSs2, in up to 120 healthy males and non-pregnant females aged 18-49, inclusive. This is a two-phase study, an outpatient WRSs2 vaccination phase and an inpatient S. sonnei 53G challenge phase. After the initiation of the study, two participants had Grade 3 diarrhea and/or vomiting in the days following vaccination. The vaccination dose was reduced to 5X10\^5, enrollment was changed to 2 arms and randomized 2:1 (vaccine: placebo). Participants with morbid obesity were excluded and weight loss medications prohibited. The Primary Objective of this study is to estimate combined vaccine efficacy of 2 doses of WRSs2 (10\^6 cfu or 5X10\^5 cfu) in preventing shigellosis, following challenge with S. sonnei strain 53G.
Study identification
- NCT ID
- NCT04242264
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 2
- Enrollment
- 69 participants
Conditions and interventions
Conditions
Interventions
- Placebo Other
- Shigella sonnei strain 53G Biological
- WRSs2 Biological
Other · Biological
Eligibility (public fields only)
- Age range
- 18 Years to 49 Years
- Sex
- All
- Healthy volunteers
- Accepts healthy volunteers
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Oct 11, 2022
- Primary completion
- Mar 10, 2024
- Completion
- Jul 7, 2024
- Last update posted
- Aug 9, 2026
2022 – 2024
United States locations
- U.S. sites
- 2
- U.S. states
- 2
- U.S. cities
- 2
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| The Hope Clinic of Emory University | Decatur | Georgia | 30030-1705 | — |
| Cincinnati Children's Hospital Medical Center Vaccine Research Center | Cincinnati | Ohio | 45229-3039 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04242264, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Aug 9, 2026 · Synced Sep 6, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT04242264 live on ClinicalTrials.gov.