Due to lack of data on safety of live vaccine in the recipient of hematopoietic stem cell transplantation, CIBMTR(Center for International Blood and Marrow Transplant Research) guidelines recommend varicella vaccination only in patients who is at least two years after transplantation and without graft versus host disease and no immunosuppressive drug.
However, recent studies have demonstrated the safety and efficacy of shingles vaccination in patients receiving hematopoietic stem cell transplantation.
But, there is no basis for timing of live vaccine administration after allo-HSCT.
The investigators plan to make scientific recommendation for optimal timing of zoster vaccine after allo-HSCT by comparing immune response between two groups(vaccination at 2 to 5years after allo-HSCT vs. 5 to 10years after allo-HSCT). Primary outcome is interferon gamma releasing ELISPOT response at week 6 after vaccination. Secondary outcome is ELISA titer for zoster-specific IgG at week 6 after vaccination.
All the patients will be asked if they have any contraindication for zoster vaccine by a physician before vaccination. And they will be monitored for any adverse reaction of the vaccination after 6 weeks(visiting the hospital).