Shigella Sonnei 53G Human Infection Study in Kenyan Adults
Status:
Not yet recruiting
Trial end date:
2026-11-30
Target enrollment:
Participant gender:
Summary
Diarrhoea caused by Shigella (shigellosis) is of major public health importance. However,
there are no licensed Shigella vaccines in routine use, with several candidates still in
various stages of clinical development. Shigella human infection studies (HIS) have played a
key role in vaccine development. These models also allow for the evaluation of immunity and
other non-immunological parameters that are important to understand resistance and/or
susceptibility to disease. This is particularly useful in individuals from endemic areas with
varying levels of prior exposure and immunity to Shigella. Thus, establishing a Shigella HIS
would enable the testing of interventions such as vaccines in a population that would most
benefit from a subsequent vaccine and has potential to accelerate vaccine development. Here,
the goal is to successfully establish a Shigella sonnei human infection model in Kenyan
adults. This will be achieved by conducting dose-finding and dose verification Shigella
studies that safely and reproducibly induce ≥60% attack rates. In this study, investigators
aim to use Shigella HIS in healthy adults to develop a model as a platform to test vaccines,
to study immune responses identifying potential correlates of infection, and
non-immunological factors mediating and influencing susceptibility to disease. To achieve
this, the study will be carried out in two phases over a period of 12-14 months. Phase A will
enroll (N=up to 40 volunteers) and Phase B will enroll an additional (N=30 volunteers). To be
eligible to receive a dose of 53G, volunteers must pass the screening visit. Investigators
will vary the dose of bacteria in individuals enrolled for challenge to identify the dose
needed to cause ≥60% shigellosis (attack rate) (Phase A) followed by testing and demonstrate
the reproducibility of the model (Phase B). Thus, the main outcomes of the study will be: (1)
optimisation of bacterial dose for infection success (≥60% attack rate); and (2) safety.
Phase:
Phase 1
Details
Lead Sponsor:
University of Oxford
Collaborators:
Johns Hopkins University KEMRI United States Army Medical Research Directorate-Kenya KEMRI-Wellcome Trust Collaborative Research Program Naval Medical Research Center PATH Walter Reed Army Institute of Research (WRAIR)