Safety Study of ProQuad® rHA in Infants (V221-037)

Inclusion Criteria: * Healthy subject of either gender, * Age from 12 to 22 months, * Negative clinical history of infection with measles, mumps, rubella, varicella or zoster, * Informed consent form signed by the parent(s) or by legal representative * Parent(s) or legal representative able to attend all schedule visits with the subject and to understand and comply with the study procedures Exclusion Criteria: * Recent (≤ 3 days) history of febrile illness * Prior receipt of measles, mumps, rubella and/or varicella vaccination, either alone or in any combination * Recent (≤ 30 days) exposure to measles, mumps, rubella, varicella or zoster * Prior known sensitivity/allergy to any component of the vaccine * Severe chronic disease, * Blood dyscrasias, leukaemia, lymphomas of any type, or other malignant neoplasms affecting the haematopoietic and lymphatic system * Any severe thrombocytopenia or any other coagulation disorder that would contraindicate intramuscular injection * Humoral or cellular immunodeficiency, * Current immunosuppressive therapy * Family history of congenital or hereditary immunodeficiency * Hereditary problems of fructose intolerance * Known personal history of encephalopathy, seizure disorder or progressive, evolving or unstable neurological condition, * Known active tuberculosis * Recent (≤ 2 days) tuberculin test or scheduled tuberculin test through Visit 3 * Receipt of immunoglobulins or blood-derived products in the past 150 days * Receipt of an inactivated vaccine in the past 14 days * Receipt of a live vaccine in the past 28 days * Any medical condition which, in the opinion of the investigator, might interfere with the evaluation of study objectives * Participation in another clinical study in the past 30 days