Study of Japanese Encephalitis Chimeric Virus Vaccine Given With Measles-Mumps-Rubella Vaccine in Taiwanese Toddlers

This study is designed to compare the immunogenicity of Japanese encephalitis chimeric virus vaccine (JE-CV) and measles-mumps-rubella (MMR)vaccine when given together or when given at separate visits 6 weeks apart in toddlers aged 12 to 18 months. Primary objective: * To demonstrate the non-inferiority of the antibody responses in terms of seroconversion of the concomitant administration of JE-CV and MMR compared to the antibody responses after the single administration of JE-CV and MMR vaccine. Secondary objectives: * To describe the immune response to JE CV and MMR before and after one dose of JE CV and MMR vaccine, respectively. * To describe the safety of a single dose of JE-CV and MMR vaccine (given separately at a 6-week interval and the safety of the concomitant administration of JE-CV and MMR vaccine in all subjects up to 6 months after last vaccination.