Study of Japanese Encephalitis Chimeric Virus Vaccine (JE-CV) in Children Previously Immunized With JE-CV

An individual had to fulfill all of the following criteria in order to be eligible for trial enrollment: All Participants * Aged 36 to 42 months on the day of inclusion * Provision of Informed Consent Form signed by at least one parent or other legally acceptable representative * Participant and parent/legally acceptable representative or guardian able to attend all scheduled visits and to comply with all trial procedures * In good general health, based on medical history and physical examination For JE-CV vaccine primed group only * Participant who was vaccinated with JE-CV in JEC02 trial (NCT00735644) An individual fulfilling any of the following criteria was excluded from trial enrollment: All Participants * Participation in another clinical trial investigating a vaccine, drug, medical device, or medical procedure in the 4 weeks preceding the trial vaccination * Planned participation in another clinical trial during the Day 0 - Month 6 period and for Group 1 up to 5 years for any flavivirus vaccine trial * Receipt of any vaccine\* in the 4 weeks preceding the trial vaccination, except for pandemic influenza vaccination, which may be received at least 2 weeks before study vaccines * Planned receipt of any vaccine\* in the 4 weeks following the trial vaccination, except for pandemic influenza vaccine. In the event of local or national immunization program with a pandemic influenza vaccine, participants who receive a pandemic influenza vaccine at any time during the trial will not be withdrawn from the trial. * Planned receipt of any JE vaccine during the course of the trial * Administration of any anti-viral within 2 months preceding the trial vaccination and up to 4 weeks following the trial vaccination * Receipt of blood or blood-derived products in the past 3 months, which might interfere with assessment of the immune response * 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 corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months) * Seropositivity for human immunodeficiency virus (HIV), hepatitis B, or hepatitis C, as reported by the parent/legally acceptable representative * History of central nervous system disorder or disease, including seizures and febrile seizures * 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 or any underlying illness (such as cardiovascular, kidney, liver or hematological disease or development abnormalities) that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion * Except in case of national immunization days with oral polio vaccine For JE-CV primed participants only * Receipt of any JE vaccine other than JE-CV during JEC02 trial(NCT00735644) and since the end of JEC02 trial For JE-CV naïve participants only * Previous vaccination against flavivirus disease including JE * History of flavivirus infection either based on clinical suspicion or laboratory proven * Previous vaccination against varicella * Previous vaccination with JE-CV in JEC02 study * History of varicella, confirmed either clinically, serologically, or microbiologically * Known systemic hypersensitivity or anaphylactic/anaphylactoid reaction to neomycin. * Known history of thrombocytopenia or idiopathic thrombocytopenic purpura Temporary Contraindications: A prospective participant was not to be included in the study until the following conditions and/or symptoms had resolved: 1. Receipt of oral or injected antibiotic therapy within 72 hours prior to the first blood draw (for Groups 1 and 2) 2. Febrile illness (temperature ≥38.0°C \[≥100.4°F\]) or moderate or severe acute illness/infection (according to investigator judgment) on the day of vaccination (for all participants) The Investigator was to postpone vaccination until the situation/condition resolved. Vaccination could be postponed within the timeframe for vaccination indicated in the protocol trial flowchart.