History of hypersensitivity to any varicella vaccine or measles, mumps, or rubella vaccine, or to neomycin. Blood dyscrasias, leukaemia, lymphomas of any type, or other malignant neoplasms affecting the haematopoietic & lymphatic system. Current immunosuppressive therapy (including high doses of corticosteroids). Severe humoral or cellular (primary or acquired) immunodeficiency. Severely immunocompromised individuals. Family history of congenital or hereditary immunodeficiency. Active untreated TB. Postpone vaccination during any illness w/ fever >38.5°C. Pregnancy. Avoid pregnancy for 1 mth following vaccination.