Immunogenicity and Safety of GSK Biologicals' Live Attenuated Varicella Vaccine (VARILRIXTM).

Inclusion Criteria: Screening phase: * A male or female ≥ 18 years of age at the time of study entry. * Written informed consent obtained from the subject prior to study entry. * Patients who are planned to undergo autologous peripheral stem cell/ bone marrow transplantation. * Subjects who the investigator believes can and will comply with the requirements of the protocol * If the subject is female, she must be of non-childbearing potential; or, if of childbearing potential, she must be abstinent or have used adequate contraceptive precautions for 30 days prior to vaccination, have a negative pregnancy test and must agree to continue such precautions for 10 months after transplantation. Active phase: * Patients who are confirmed to have undergone autologous peripheral stem cell/ bone marrow transplantation. * If the subject is female, she must be of non-childbearing potential; or, if of childbearing potential, she must be abstinent or have used adequate contraceptive precautions for 30 days prior to vaccination, have a negative pregnancy test and must agree to continue such precautions for 10 months after transplantation. Exclusion Criteria: Screening phase: * Pregnant or lactating female. * Female planning to become pregnant or planning to discontinue contraceptive precautions in the 10 months post-transplantation. * History of allergy to any component of the vaccine. * Patients with difficult to treat disease who are likely to relapse within 6 months post-transplantation. * Current drug and/or alcohol abuse. Active phase: * Use of any investigational or non-registered product (drug or vaccine) during the active phase of the study period. * Use of immunosuppressants or other immune-modifying drugs within 14 days preceding the administration of the first dose of the study vaccine or planned use during the active phase of the study period. * Use of rituximab (MabThera) more than 60 days after transplant. * Administration of a vaccine not foreseen by the study protocol during the period starting from 30 days before each dose of vaccine and ending 30 days after. * Pregnant or lactating female. * Female planning to become pregnant or planning to discontinue contraceptive precautions in the 10 months post-transplantation. * History of allergy to any component of the vaccine * Patients with VZV disease after transplantation and prior to vaccination. * Ongoing requirement for antiviral therapy with anti-VZV activity beyond 4 months post-transplantation * Patients with difficult to treat disease who are likely to relapse within 6 months post-transplantation. * Current drug and/or alcohol abuse.