Immunogenicity & Safety Study of GSK Biologicals' Combined Measles-mumps-rubella-varicella Vaccine 208136

Inclusion Criteria: * Subjects who the investigator believes that their parents/guardians can and will comply with the requirements of the protocol should be enrolled in the study. * A male or female between, and including 11 and 24 months of age, at the time of the vaccination. * Written informed consent obtained from the parent or guardian of the subject. * Healthy subjects 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 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 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 the study vaccine dose with the exception of inactivated vaccines such as pneumococcal, Haemophilus influenzae type b conjugate vaccines, inactivated influenza, hepatitis A or B vaccine or diphtheria/tetanus-containing vaccines which can be administered up to eight days before the study vaccine dose. * Previous vaccination against measles, mumps, rubella and/…