A Study to Determine If a New Shigella Vaccine is Safe, Induces Immunity and The Best Dose Among Kenyan Infants

Inclusion Criteria: All ages * Healthy by medical history, laboratory findings and physical examination before entering into the study (Participants with a minor illness (such as mild diarrhoea, mild upper respiratory infection) without fever may be enrolled at the discretion of the investigator) * Seronegative for HIV, hepatitis B and C (as per screening laboratory tests) * Resident in the study area village during the whole trial period (Kilifi -Kilifi Health and Demographic Surveillance System (Described in more detail in the SSA); (Kericho-a 75km radius from the Kericho Clinical Research Centre). * Previously completed routine primary vaccinations (6,10 and 14 weeks or thereabouts) to the best knowledge of the participant/parent/guardian. * Signed/thumb written informed consent, in accordance with local practice, provided by adult volunteers (participants 18 years of age and older), parents or legal representatives for children and infants participants as applicable, who, in the opinion of the investigator, can and will comply with the requirements of the protocol * Demonstrated comprehension of the protocol procedures by passing score of 90% or better on a written/verbal comprehension test. Adults * Female and male participants between, and including 18-50 years at the time of first vaccination * Female participants of non-childbearing potential may be enrolled in the study. Non-childbearing potential is defined as pre-menarche, current bilateral tubal ligation or oc…