Actively Recruiting
Shigella Sonnei 53G Human Infection Study in Kenyan Adults
Led by University of Oxford · Updated on 2025-03-13
70
Participants Needed
1
Research Sites
135 weeks
Total Duration
On this page
Sponsors
U
University of Oxford
Lead Sponsor
K
KEMRI-Wellcome Trust Collaborative Research Program
Collaborating Sponsor
AI-Summary
What this Trial Is About
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.
CONDITIONS
Official Title
Shigella Sonnei 53G Human Infection Study in Kenyan Adults
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Healthy adults between 18 and 45 years of age (inclusive) residing in Kilifi County
- Able and willing to comply with all study requirements
- Provide informed consent
- Pass a comprehension test of study procedures with 100% score
- Use an effective contraception method throughout the study duration (women only), with verification by family planning records
- Willing to participate in an inpatient stay lasting about 12 days and outpatient follow-up for about 12 months
- Available for all planned follow-up visits
You will not qualify if you...
- Having significant medical conditions such as psychiatric illness, substance abuse, or gastrointestinal diseases
- Known immunosuppressive illnesses or treatments, including cancer, HIV, or immunosuppressive therapy
- Positive test results for HIV, hepatitis B surface antigen, or hepatitis C antibodies
- Evidence or family history of inflammatory arthritis
- Abnormal blood or chemistry lab results deemed significant by the investigator
- Allergies to fluoroquinolones, beta-lactams, or trimethoprim-sulfamethoxazole
- Having abnormal stool frequency (less than 3 stools per week or more than 3 stools per day)
- Recent diarrhea within 2 weeks prior to inpatient phase
- Antibiotic use within 7 days before receiving the challenge dose
- Use of certain medications (imodium, acetaminophen, aspirin, ibuprofen, NSAIDs) within 48 hours before challenge
- Positive PCR test for SARS-CoV-2 three days before challenge
- Use of medications affecting immune function within 30 days before challenge or planned use during study
- Prior Shigella sonnei infection as shown by serology
- Unstable chronic disease medication doses within last 3 months
- Living with immunocompromised household contacts
- Abnormal vital signs or clinical findings
- Pregnancy, breastfeeding, or planning pregnancy within 29 days of study product
- Living with or having daily contact with high-risk groups (elderly, infants, pregnant women, immunocompromised) for 4 weeks after challenge
- Working in healthcare, daycare, or food handling in 4 weeks after challenge
- Use of investigational drugs or vaccines within specified timeframes
- Recent receipt of licensed vaccines within 14 to 28 days prior to challenge
- Inability to follow inpatient rules
- Any other condition that might risk safety or compliance
- Received blood products within past 6 months
AI-Screening
AI-Powered Screening
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Trial Site Locations
Total: 1 location
1
KEMRI-Wellcome Trust Research Programme
Kilifi, Kenya, 80108
Actively Recruiting
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NON_RANDOMIZED
Model
SEQUENTIAL
Primary Purpose
BASIC_SCIENCE
Number of Arms
6
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