• Safety (including the proportion of subjects reporting adverse events (AEs) and serious adverse events (SAEs)). [ Time Frame: From day of dosing to 28 days post-dosing under double-blind conditions with 3 month open follow-up ] [ Designated as safety issue: No ]
  
• Immunogenicity (level of IgG and IgA antibodies for Salmonella typhi lipopolysaccharide post-dosing, in comparison to baseline levels). [ Time Frame: Days 7, 14 and 28 post-dosing ] [ Designated as safety issue: No ]
  

• Immunogenicity (Number of cells secreting IgA antibodies for Salmonella typhi lipopolysaccharide) [ Time Frame: Day 7 post-dosing ] [ Designated as safety issue: No ]
  

Inclusion Criteria:

• healthy adult subjects aged 18 to 50 years inclusive, who are able and willing to give informed consent, following a detailed explanation of participation in protocol
• available for the duration of the study and available for scheduled and potential additional visits

Exclusion Criteria:

• women who are pregnant, breast-feeding or of childbearing potential and unwilling to use a reliable method of contraception throughout the study period
• history of anaphylactic shock following vaccination by any route have phenylketonuria
• hypersensitivity to any component of the vaccine or are hypersensitive to two of the following antibiotics: ciprofloxacin, azithromycin, ampicillin, trimethoprim sulfamethoxazole
• received antibiotic medication within 14 days prior to dosing
• received any vaccine within 4 weeks prior to dosing or plan to receive a vaccine within 4 weeks after dosing
• received any vaccine against Salmonella typhi (licensed or investigational) or ever suffered from typhoid fever
• subjects who test positive for hepatitis B, hepatitis C, HIV or human leucocyte antigen B-27
• known or suspected history of liver or active gall bladder disease, ongoing gastro-intestinal disease or abnormality
• commercial food handlers or health care workers with direct contact with high risk patients or who have household contacts with immuno-compromised individuals, pregnant women or children less than 2 years of age
• subjects who have a clinically significant amount of protein or haemoglobin in their urine or abnormality of their haematology or serum biochemistry parameters
• impairment of immune function or those receiving or have received cytotoxic drugs in the 6 months prior to study entry
• subjects who use antacids, proton pump inhibitors or H2 blockers on a regular basis or have consumed proton pump inhibitors or H2 blockers within 24 hours prior to dosing
• acute infections (including fever of 37.5 degrees Celsius or greater) on the day of dosing.
• subjects with chronic disease (e.g Crohn's disease, inflammatory bowel disease, diabetes) who cannot withstand a 3 hour fast
• substance abuse or a history of substance abuse that might interfere with participation in the study
• body mass index (BMI) is less than 19 or greater than 34 kg per m2
• clinically significant medical condition that precludes participation in the study
• subjects who have participated in an interventional clinical trial within 60 days of dosing