Safety and Immunogenicity of Vi-CRM197 Vaccine Against S. Typhi in Adults, Children, Older Infants and Infants

Main eligibility criteria: * Subjects belonging to 4 age groups will be enrolled into the trial: adults (18 to 45 years of age), children (24 to 59 months of age), older infants (9 to 12 months of age at enrollment) and infants (6 weeks of age at enrolment). * Written informed consent will be obtained by the all subjects or their parents/ guardians (depending on the age group) before enrollment into the trial. * Only females with a negative pregnancy test and willing to participate in family planning consultations (organized by the site study team) will be allowed to participate to the trial. * Infants who have been vaccinated with 1 dose of BCG, HBV and OPV at birth can be enrolled into the trial, while infants who have received DTwP+HBV+Hib or OPV due at 6 weeks of age as per local EPI schedule cannot be enrolled into the trial.