This study is to assess the safety and immunogenicity of Vi-DT vaccine in adults, adolescent, children and infants.

To describe the safety of this vaccine following one dose immunization in adults, adolescent, children and infants.

To assess immunogenicity following one dose of Vi-DT vaccine immunization. To compare the safety and immunogenicity of Vi-DT to Vi polysaccharide vaccine in adults, adolescents, and children groups.

To compare the safety and immunogenicity of Vi-DT to IPV vaccine in infants groups.

Kinetics of Vi-specific IgG antibodies up to 6 months and 1 year after administration of 1 dose of vaccine.

To evaluate the safety and immunogenicity of Vi-DT co-administered with MR vaccine in infants (≥ 9months -23 months old).

To evaluate the safety and immunogenicity of MR vaccine co-administered with Vi-DT vaccine in infants (≥ 9months -23 months old).

Inclusion Criteria:

1. Healthy
2. Subjects/Parents have been informed properly regarding the study and signed the informed consent form
3. Subject/parents/legal guardians will commit themselves to comply with the instructions of the investigator and the schedule of the trial.

Exclusion Criteria For adults-adolescent-children:

1. Subject concomitantly enrolled or scheduled to be enrolled in another trial
2. Evolving mild, moderate or severe illness, especially infectious diseases or fever (axillary temperature ³ 37.5°C)
3. Known history of allergy to any component of the vaccines
4. History of uncontrolled coagulopathy or blood disorders contraindicating intramuscular injection
5. Subject who has received in the previous 4 weeks a treatment likely to alter the immune response (intravenous immunoglobulins, blood-derived products, corticosteroid therapy and other immunosuppresant).
6. Any abnormality or chronic disease which according to the investigator might interfere with the assessment of the trial objectives
7. Pregnancy & lactation (Adults)
8. Individuals who have previously received any vaccines against typhoid fever.
9. Subjects already immunized with any vaccine within 1 month prior and expect to receive other vaccines within 1 month following immunization.
10. Individuals who have a previously ascertained typhoid fever within 3 months prior to immunization.
11. History of substance abuse (Adults).
12. Subject planning to move from the study area before the end of study period.

Exclusion Criteria for infants:

1. Subject concomitantly enrolled or scheduled to be enrolled in another trial
2. Mother less than 18 years of age at the age of enrollment of the infant
3. Evolving mild, moderate or severe illness, especially infectious diseases or fever (axillary temperature ³ 37.5°C)
4. Known history of allergy to any component of the vaccines
5. History of uncontrolled coagulopathy or blood disorders contraindicating intramuscular injection
6. Subject who has received in the previous 4 weeks a treatment likely to alter the immune response (intravenous immunoglobulins, blood-derived products, corticosteroid therapy and other immunosuppresant).
7. Any abnormality or chronic disease which according to the investigator might be compromised by the vaccination and/or interfere with the assessment of the trial objectives.
8. Individuals who have previously received any vaccines against typhoid fever.
9. Subjects already immunized with any vaccine within 1 month prior and expect to receive other vaccines within 1 month following immunization, except MR vaccine.
10. Individuals who have a previously ascertained typhoid fever within 3 months prior to immunization.
11. Subject planning to move from the study area before the end of study period.

Subject aged 2 - 40 years old:

Randomized, observer-blind, superiority design compared to Vi polysaccharide vaccine.

Subject 6-23 months old:

Randomized, observer-blind, superiority design compared to Inactivated Poliomyelitis Vaccine (IPV).