Phase 2 Shigella Vaccine and Challenge

Completed · Phase 2 · Has a placebo group

Conditions studied: Immunisation, Shigella Infection

In brief

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.

Key facts

Study ID
NCT04242264
Run by
National Institute of Allergy and Infectious Diseases (NIAID)
People needed
69
Starts
2022-10-12
Expected to finish
2024-07-08
Last updated by the study team
2026-08-10

Who can join

Age: 18 and older, up to 49. Sex: any. Healthy volunteers: accepted.

You may qualify if…

You may not qualify if…

Where it is running

Full record on ClinicalTrials.gov

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