Eligibility Criteria:
Inclusion Criteria:
All participants:
* Participants and/or participants' parent(s)/legally acceptable representative(s) LAR(s), who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g. completion of the diary cards, return for follow-up visits).
* Written or witnessed/thumb printed informed consent obtained from the participant/parent(s)/LAR(s) of the participant prior to performance of any study specific procedure.
* Healthy participants as established by medical history, clinical examination, and laboratory assessment.
* Participants satisfying all screening requirements.
* Participants seronegative for hepatitis B, and hepatitis C.
* Participants negative for human leukocyte antigen B27 (HLA-B27).
Adults 18 to 50 years of age:
* A male or female between, and including, 18 and 50 years of age at the time of the first study intervention administration.
* 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 occlusion, hysterectomy, bilateral ovariectomy or post-menopause.
* Female participants of childbearing potential may be enrolled in the study, if the participant:
\- has practiced adequate contraception for 1 month prior to study intervention administration, and
\- has a negative pregnancy test on the day of study intervention administration, and
* has agreed to continue adequate contraception during the entire treatment period and for 1 month after completion of the study intervention administration series.
* Participants seronegative for human immunodeficiency virus (HIV).
Children 24 to 59 months of age:
* A male or female between, and including, 24 and 59 months of age at the time of first vaccination.
* Normal nutritional Z score (-2 standard deviation or greater).
* Previously completed routine childhood vaccinations to the best knowledge of the participant's parent(s)/LAR(s).
* Born after gestation period of ≥37 weeks.
* Participants seronegative for HIV.
Infants 9 months of age:
* A male or female 9 months of age at the time of first vaccination.
* Normal nutritional Z score (-2 standard deviations or greater).
* Previously completed routine childhood vaccinations to the best knowledge of the participant's parent(s)/LAR(s).
* Born after a gestation period of ≥37 weeks.
* Participants negative for HIV as confirmed by deoxyribonucleic acid (DNA) polymerase chain reaction (PCR) testing.
Exclusion Criteria:
All participants:
* Known exposure to Shigella during lifetime of the participant as confirmed during interview with the participant or documented by patient records (e.g., history of microbiologically-confirmed Shigella infection), recent travel\* (within 2 years) to a country where Shigella or other enteric infections are endemic, or recent occupation\* (within 3 years) involving Shigella species.
\*Exclusion due to travel or occupation is applicable only to Adults 18 to 50 years of age in Europe (Stage 1).
* Progressive, unstable or uncontrolled clinical conditions.
* History (known or suspected) of any reaction or hypersensitivity likely to be exacerbated by any component of the study vaccine.
* Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required).
* Hypersensitivity, including allergy, to medicinal products or medical equipment whose use is foreseen in this study.
* Clinical conditions representing a contraindication to IM vaccination and blood draws.
* Any behavioural or cognitive impairment or psychiatric disease that, in the opinion of the investigator, may interfere with the participant's ability to participate in the study.
* Acute disease and/or fever (defined as temperature ≥38.0°C) at the time of enrolment\*.
* The participant can still be enrolled into the study at a time when the acute disease and/or fever has resolved.
* Any clinically significant haematological and/or biochemical laboratory abnormality.
* Confirmed positive COVID-19 test during the period starting 30 days before the first administration of study vaccines (Day -30 to Day 1).
* Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the study.
* Administration of long-acting immune-modifying drugs at any time during the study period (e.g. infliximab).
* Prior receipt of an experimental Shigella vaccine or live Shigella challenge.
* Use of any investigational or non-registered product (drug, vaccine or medical device)\* other than the study vaccine during the period starting 30 days before the first dose of study intervention (Day -30 to Day 1), or planned use during the study period.
\*Use of herbs and traditional treatments is not considered an exclusion criterion
* A vaccine not foreseen\* by the Study Protocol administered during the period starting at -21 days before the first dose (-28 days in the case of live vaccines) and ending after the last dose of study intervention administration\*\*.
\*Vaccines allowed by the Protocol include flu and COVID-19 vaccines in all participants and EPI vaccines in children and infants.
\*\*In case of emergency mass vaccination, the time period above can be reduced.
* Concurrently participating in another clinical study, at any time during the study period, in which the participant has been or will be exposed to an investigational or a non-investigational intervention (drug or invasive medical device).
* Any study personnel or immediate dependents, family, or household member.
Adults 18 to 50 years of age:
* Acute or chronic illness, clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by physical examination or laboratory screening tests.
* Chronic administration (defined as more than 14 days in total) of immunosuppressants or other immune-modifying drugs during the period starting 3 months prior to the first vaccine study intervention. For corticosteroids, this will mean prednisone equivalent ≥20 mg/day for adult participants. Inhaled and topical steroids are allowed.
* Pregnant or lactating female.
* Female planning to become pregnant or planning to discontinue contraceptive precautions.
* History of or current chronic alcohol consumption and/or drug abuse.
Adults 18 to 50 years of age and Children 24 to 59 months age:
• Administration of immunoglobulins and/or any blood products or plasma derivatives, or bone marrow transplantation, during the period starting 3 months before the first dose of study vaccine or planned administration during the study period.
Children 24 to 59 months of age and infants 9 months of age:
* Acute or chronic clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by physical examination or laboratory screening tests.
* Chronic administration (defined as more than 14 days in total) of immunosuppressants or other immune-modifying drugs during the period starting 3 months prior to the first vaccine dose. For corticosteroids, this will mean prednisone ≥0.5 mg/kg/day or 20 mg/day whichever is the maximum dose for paediatric participants. Inhaled and topical steroids are allowed.
* Child in care.
Infants 9 months of age:
• Administration of immunoglobulins and/or any blood products or plasma derivatives, or bone marrow transplantation, from birth or planned administration during the study period.