This trial is aimed to evaluate the safety and immunogenicity profiles of a new Vi-CRM197 conjugate vaccine against S. Typhi in healthy human adults in comparison with the currently licensed Vi polysaccharide vaccine.

Inclusion Criteria:

1. Males and females of age ≥18 to ≤40 years.
2. Individuals who, after the nature of the study has been explained to them, have given written consent according to local regulatory requirements.
3. Individuals in good health as determined by the outcome of medical history, physical examination, hematological / hematochemical blood tests and urinalysis and clinical judgment of the investigator.
4. If women, a negative pregnancy test and willingness to use birth control measures for the entire study duration

Exclusion Criteria:

1. Individuals with behavioral or cognitive impairment or psychiatric disease that, in the opinion of the investigator, may interfere with the subject's ability to participate in the study.
2. Individuals with any progressive or severe neurological disorder, seizure disorder or Guillain-Barré syndrome.
3. Individuals who are not able to understand and to follow all required study procedures for the whole period of the study.
4. Individuals with history of any illness that, in the opinion of the investigator, might interfere with the results of the study or pose additional risk to the subjects due to participation in the study.
5. Individuals with known or suspected HIV infection or HIV related disease, with history of an autoimmune disorder or any other known or suspected impairment /alteration of the immune system, or under immunosuppressive therapy including use of systemic corticosteroids or chronic use of inhaled high-potency corticosteroids within the previous 30 days, or were in chemotherapy treatment within the past 6 months.
6. Individuals with a known bleeding diathesis, or any condition that may be associated with a prolonged bleeding time.
7. Individuals with any serious chronic or progressive disease according to judgment of the investigator.
8. Individuals who have any malignancy or lymphoproliferative disorder.
9. Individuals with history of allergy to vaccine components.
10. Individuals participating in any clinical trial with another investigational product 30 days prior to first study visit or intent to participate in another clinical study at any time during the conduct of this study.
11. Individuals who have previously received any vaccines against typhoid fever.
12. Individuals who received any other vaccines within 4 weeks prior to enrollment in this study or who are planning to receive any vaccine within 4 weeks from the study vaccine.
13. Individuals who have received blood, blood products and/or plasma derivatives including parenteral immunoglobulin preparations in the past 12 weeks.
14. Individuals with body temperature > 38.0 degrees Celsius within 3 days of intended study immunization.
15. BMI > 35 kg/m2.
16. Individuals with history of substance or alcohol abuse within the past 2 years.
17. Women who are pregnant or breast-feeding or of childbearing age who have not used or do not plan to use acceptable birth control measures, for the duration of the study.
18. Females with history of stillbirth, neonatal loss, or previous infant with anomaly.
19. Individuals who have a previously ascertained or suspected disease caused by S. Typhi.
20. Individuals who have had household contact with/and or intimate exposure to an individual with laboratory confirmed S. Typhi.

AE during 28 days following vaccination (SAE for 6 months)