Vaccination after stem cell transplant: a review of recent developments and implications for current practice

Abstract

We have seen significant advances in the fields of stem cell transplantation and vaccinology. However, vaccination practices after transplantation remain varied and data sparse. We review recent changes in adult stem cell transplantation that pertain to vaccination practice, and discuss the evidence guiding the use of established and newly approved vaccines. Infection remains an important cause of morbidity and mortality in the stem cell transplant population. To extend stem cell transplantation to an increased number of patients and to widen the sources of donor cells, nonmyeloablative stem cell transplantation and cord blood transplantation have been used with increased frequency. These newer modalities differ in their immunological deficits, risk of infection and response to vaccination. Alternate vaccination regimens such as vaccination of either donors or recipients or both prior to stem cell harvest and early repeated vaccination after transplantation have been investigated. The full utility of these methods has yet to be delineated. The safety and benefit of new vaccines such as the acellular pertussis, human papilloma virus or varicella virus vaccine have yet to be formally investigated. We would argue that their use may be appropriate in the right setting. The complexity of stem cell transplantation continues to evolve and so must vaccine practices in this population. New vaccines that have the potential to improve long-term outcome should be investigated.