This is a research study of an experimental (investigational) live attenuated Shigella sonnei vaccine (WRSS1) to find a dose of the vaccine that is safe, tolerable, and develops an immune response. Shigella causes bloody and watery diarrhea, and infants and children living in developing countries experience the greatest consequences of this disease.
Who can participate
Age range
12 Months – 24 Months
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Male or female children aged between 12 to 24 month of age at the time of vaccination
. General good health as determined by the screening evaluation no greater than 30 days before admission
. Father, mother or other legally acceptable representative (guardian) properly informed about the study, able to understand it and sign the informed consent form
. Normal bowel habits (\< 3 grade 1 or 2 stools each day; ≥ 1 grade 1 or 2 stools every 2 days)
. Free of obvious health problems as established by medical history and clinical examination before entering into the study.
. Parent or guardian available for the entire period of the study and reachable by study staff throughout the entire follow-up period.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Maximum Severity of Reactogenicity by Vaccination
Timeframe: 72 hours after each vaccination (Day 3, Day 31, Day 59)
2
Number of Participants With Adverse Events Occurring Within 28 Days After Any Vaccination by Maximum Severity
Timeframe: Up to 28 days after any vaccination (up to Day 84)
. Signed Informed Consent from the Parent or legal guardian
Exclusion criteria
. Presence of a significant medical that in the opinion of the Investigator precludes participation in the study
. Known infection with human immunodeficiency virus (HIV)
. Presence in the serum of hepatitis A virus (HAV) or hepatitis C virus (HCV) antibody.
. History of congenital abdominal disorders, intussusception, abdominal surgery or any other congenital disorder.
. Participation in research involving another investigational product (defined as receipt of investigational product) 30 days before planned date of first vaccination or concurrently participating in another clinical study, at any time during the study period, in which the child has been or will be exposed to an investigational or a non-investigational product
. Clinically significant abnormalities on physical examination
. Clinically significant abnormalities in screening hematology, serum chemistry as determined by the PI or the PI in consultation with the Study Physician
. History of febrile illness within 48 hours prior to vaccination