Study of a Booster Dose of IMOJEV® One Year After Primary Immunization in Healthy Children in South Korea

Inclusion Criteria: * Must have participated in study JEC12 and received 1 dose of IMOJEV at least 12 months before booster vaccination * Age 2 to 4 years on the day of inclusion * In good general health at the time of inclusion * Informed Concent Form signed and dated by parent(s) or another legally acceptable representative(s) * Subject and parent(s)/legally acceptable representative(s) able to attend all scheduled visits and comply with all study procedures. Exclusion Criteria: * Participation at the time of study enrollment (or in the 4 weeks preceding the trial vaccination) or planned participation during the present trial period in another clinical study investigating a vaccine, drug, medical device, or a medical procedure in the 4 weeks preceding the study vaccination * Known or suspected congenital or 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 * Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccine used in the trial or to a vaccine containing any of the same substances * Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion * Receipt of immune globulins, blood or blood-derived products in the past 3 months, that might interfere with the assessment of the immune response * Previous vaccination against flavivirus disease, including JE, with another vaccine, except with IMOJEV® while participating in JEC12 * Administration of any anti-viral within 2 months preceding Visit 1 and up to the 4 weeks following the study vaccination * Receipt of any vaccine in the 4 weeks preceding the trial vaccination or planned receipt of any vaccine in the 4 weeks following the trial vaccination, except for inactivated influenza vaccination, which may be received at least 2 weeks before the study vaccine * History of central nervous system disorder or disease, including seizures * Planned receipt of any JE vaccine during the course of the study * History of flavivirus infection (confirmed either clinically, serologically or virologically) * Administration of systemic corticosteroids for more than 2 consecutive weeks within the 4 weeks preceding vaccination * Thrombocytopenia, contraindicating vaccination * Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating vaccination * Febrile illness (temperature ≥38.0°C) or moderate or severe acute illness/infection 3 days before vaccination as well as the day of vaccination, according to Investigator judgment. A prospective subject should not be included in the study until the condition has resolved or the febrile event has subsided * In an emergency setting or hospitalized involuntarily * Identified as a natural or adopted child of the Investigator or employee with direct involvement in the proposed study.