A Study on the Immune Response and Safety of a Multicomponent Shigella Vaccine in Preventing Shigellosis in Infants

Inclusion Criteria:

• Participants' parent(s)/ Legally acceptable representative (LAR), who, in theopinion of the investigator, can and will comply with the requirements of theprotocol.

• Written or witnessed/thumb printed informed consent obtained from theparent(s)/LAR(s) of the participant prior to performance of any study specificprocedure.

• Healthy participants as established by medical history, clinical examination, andlaboratory assessment.

• Participants satisfying all screening requirements.

• Participants seronegative for hepatitis B, and hepatitis C.

• A male or female 9 months of age at the time of the first study interventionadministration.

• Normal nutritional z-score.

• Previously completed routine childhood vaccinations to the best knowledge of theparticipant's parent(s)/LAR(s).

• Born at a gestation period of >=37 weeks to the best knowledge of the participant'sparent(s)/LAR(s).

• Participants negative for human immunodeficiency virus as confirmed by DNApolymerase chain reaction testing.

• Participants negative for HLA-B27.

Exclusion Criteria:

• Known exposure to Shigella during lifetime of the participant as confirmed duringinterview with the participant's parent(s)/LAR(s) or documented by participant'srecords.

• Progressive, unstable, or uncontrolled clinical conditions.

• History (known or suspected) of any reaction or hypersensitivity likely to beexacerbated by any component of the study intervention.

• Major congenital defects, as assessed by the investigator.

• Recurrent history or uncontrolled neurological disorders or seizures.

• Any confirmed or suspected immunosuppressive or immunodeficient condition, based onmedical history and physical examination.

• Hypersensitivity (known or suspected), including allergy, to medicinal products,vaccines, or medical equipment whose use is foreseen in this study.

• Clinical conditions representing a contraindication to intramuscular vaccination andblood draws.

• Any behavioral or cognitive impairment or psychiatric disease that, in the opinionof the investigator, may interfere with the participant's ability to participate inthe study.

• Acute disease and/or fever (defined as temperature >=38.0°C) at the time ofenrollment.

• Any clinically significant hematological and/or biochemical laboratory abnormality.

• Confirmed positive COVID-19 test during the period starting 30 days before the firstadministration of study interventions (Day -30 to Day 1).

• Any other clinical condition that, in the opinion of the investigator, might poseadditional risk to the participant due to participation in the study.

• Acute or chronic clinically significant pulmonary, cardiovascular, hepatic, or renalfunctional abnormality, as determined by physical examination or laboratoryscreening tests.

• Use of any investigational or non-registered product (drug, vaccine or invasivemedical device) other than the study intervention(s) during the period beginning 30days before the first dose of study intervention(s) (Day -30 to Day 1), or theirplanned use during the study period.

• Planned administration/administration of a vaccine/product not foreseen by theProtocol in the period starting 21 days before the first dose and ending after thelast dose of study intervention(s) administration with the exception of Coronavirusdisease 2019 (COVID-19) vaccines and Expanded Program on Immunization (EPI)vaccines.

• Administration of long-acting immune-modifying drugs at any time during the studyperiod.

• Prior receipt of an experimental Shigella vaccine or live Shigella challenge.

• Prior receipt of a Typhoid conjugate vaccine (TCV).

• Administration of immunoglobulins and/or any blood products or plasma derivatives,or bone marrow transplantation, from birth or planned administration during thestudy period.

• Chronic administration of immune-modifying drugs (defined as more than 14 daysconsecutive days in total) and/or planned use of long-acting immune-modifyingtreatments at any time up to the end of the study.

• Concurrently participating in another clinical study, at any time during the studyperiod, in which the participant has been or will be exposed to an investigationalor a non-investigational intervention drug or invasive medical device.

• Any study personnel or immediate dependents, family, or household member.

• Child in care.

• Participants who do not meet eligibility criteria for administration of controlvaccines.