Immunogenicity & Safety Study of GSK Biologicals' 208136 Vaccine Formulated With New Measles and Rubella Working Seeds

Inclusion Criteria: * Subjects who the investigator believes that their parents/guardians can and will comply with the requirements of the protocol (e.g. completion of the diary cards, return for follow-up visits) should be enrolled in the study. * A male or female between, and including, 11 and 21 months of age (e.g. from age 11months until the day before age 22 months) at the time of the first vaccination. * Written informed consent obtained from the parent or guardian of the subject after they have been advised on the risks and benefits of the study in a language they clearly understand, and before performance of any study procedure. * Free of obvious healthy problems as established by medical history and clinical examination before entering into the study. Exclusion Criteria: * Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine(s) within 30 days preceding the first dose of study vaccine, or planned use during the study period. * Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs within six months prior to the first vaccine dose. * Administration of immunoglobulins and/or any blood products during the six months before entering the study or planned administration during the study period. * Planned administration/ administration of a vaccine not foreseen by the study protocol within 30 days prior to until 42 days after each study vaccine dose with the exception of or…