This study is designed to assess the immunogenicity and safety of typhoid Vi polysaccharide vaccine in Japanese participants to support registration of the product in Japan.

Primary Objective:

To describe the seroconversion rate (percentage of subjects with at least a 4-fold increase of their Vi antibody titer) between Day 0 before vaccination and Day 28 after vaccination with typhoid Vi polysaccharide (SP093) vaccine in subjects aged 2 years and above.

Secondary Objectives:

• To describe the safety profile of a single dose of typhoid Vi polysaccharide vaccine up to 28 days after vaccination, in subjects aged 2 years and above.
• To describe the immune response following a single dose of typhoid Vi polysaccharide vaccine in subjects aged 2 years and above.

All participants will receive a single dose of typhoid Vi polysaccharide vaccine on Day 0 and be assessed for immunogenicity on Day 0 before vaccination and on Day 28 post-vaccination. All participants will be monitored for safety for up to 28 days post-vaccination.

Inclusion Criteria:

• Aged 2 years and above on the day of inclusion
• For subjects ≥ 20 years of age: Informed consent form has been signed and dated by the subjects. For subjects 2 to 19 years of age: Informed consent form has been signed and dated by the parent or other legally representative. Also subjects 7 to 11 years of age will provide oral assent and subjects 12 to 19 years of age will provide written assent form
• Able to attend all scheduled visits/phone call and to comply with all trial procedures
• For a woman of childbearing potential, use of an effective method of contraception from at least 4 weeks prior to vaccination until at least 4 weeks after vaccination.

Exclusion Criteria:

• Any acute and/or serious disease/illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion
• History of typhoid fever or Salmonella typhi infection, confirmed either clinically, serologically, or microbiologically
• Known systemic hypersensitivity to any of the vaccine components, or history of a life threatening reaction to a vaccine containing the same substances of the study vaccine
• Known or suspected congenital or current/previous acquired immunodeficiency; or receipt of immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months; or long-term systemic corticosteroids therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months)
• Participation in another clinical trial investigating a vaccine, drug, medical device, or medical procedure in the 4 weeks preceding the trial inclusion
• Planned participation in another clinical trial during the present trial period
• Receipt of blood or blood-derived products in the past 3 months, which might interfere with assessment of the immune response
• Receipt of any vaccine within the four weeks preceding the trial vaccination, except for influenza vaccination, which may be received at least two weeks before the study vaccine
• Planned receipt of any vaccine during the trial period
• Clinical or known serological evidence of systemic illness including hepatitis B, hepatitis C and/or Human immunodeficiency virus (HIV) infection
• Ineligible according to the investigator's clinical judgment
• Known pregnancy, or a positive (serum and/or urine) pregnancy test
• Currently breastfeeding a child
• Known thrombocytopenia, contraindicating intramuscular (IM) vaccination
• Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating IM vaccination
• Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily
• Current alcohol abuse or drug addiction that might interfere with the ability to comply with trial procedures
• Identified as employee of the Investigator or study center, with direct involvement in the proposed study or other studies under the direction of that Investigator or study center, as well as family member (i.e., immediate, husband, wife and their children, adopted or natural) of the employees or the Investigator
• Previous vaccination against Salmonella typhi disease with either the trial vaccine or another vaccine.

Adverse event data were collected from Day 0 (post vaccination) up to Day 28 post vaccination.