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Phase 2 Shigella Vaccine and Challenge

NCT04242264 · Status: COMPLETED · Phase: PHASE2 · Type: INTERVENTIONAL · Enrollment: 69

Last updated 2025-04-24

Study results available
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Summary

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.

Conditions

  • Immunisation
  • Shigella Infection

Interventions

OTHER

Placebo

0.9% Sterile Normal Saline, USP

BIOLOGICAL

Shigella sonnei strain 53G

1.5 x 10\^3 Colony Forming Units (cfu) Shigella sonnei 53G, a virulent strain of wildtype Shigella sonnei

BIOLOGICAL

WRSs2

10\^6 Colony Forming Units (cfu) dose of an oral live-attenuated Shigella sonnei vaccine candidate derived from a virulent S. sonnei strain Moseley (WRSs2)-a live, attenuated vaccine that has been manufactured under cGMP conditions at the WRAIR PBF

Sponsors & Collaborators

  • National Institute of Allergy and Infectious Diseases (NIAID)

    lead NIH

Study Design

Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Model
PARALLEL

Eligibility

Min Age
18 Years
Max Age
49 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2022-10-12
Primary Completion
2024-03-11
Completion
2024-07-08
FDA Drug
Yes

Countries

  • United States

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT04242264 on ClinicalTrials.gov