Heat inactivated VZV vaccine has been shown to more than halve the incidence of herpes zoster in adult BMT patients undergoing autologous transplantation. Clinical protection was correlated with in vitro CD4 T-cell proliferation in response to varicella-zoster virus. Being a live vaccine, attenuated VZV and (herpes zoster (HZ) vaccines are contraindicated within 24 months after allogeneic HSCT. However, priming of donor T-cells with herpes zoster vaccine may be a feasible alternative. One possible complication is the transfer of live virus from vaccinated donors to immunocompromised stem cell transplant recipients.