Immunogenicity and Safety of Combined Vaccine to Prevent Measles, Mumps, Rubella and Chickenpox Diseases

Inclusion Criteria: * A male or female subject between 11-13 months of age (i.e. from 11 month birthday until the day before the 14 month birthday) at the time of the first vaccination. Exclusion Criteria: * History of previous measles, mumps, rubella and/or varicella vaccination or disease, or known exposure to any of these diseases within 30 days prior to the start of the trial * Planned administration of a vaccine not foreseen by the study protocol from 30 days prior to each vaccination until 42-56 days after each vaccination