Live (vaccines) from New York

Abstract

Over 40 000 hematopoietic cell transplantations (HCT) are performed worldwide each year, increasing the number of transplant survivors returning to school, the work place and overseas travel. Outbreaks of measles and mumps in immunocompetent individuals and the increased morbidity associated with primary varicella and shingles in older individuals highlight the need for effective vaccination of these vulnerable patients. In current post-HCT vaccination guidelines, only the measles, mumps and rubella vaccine (MMR) and the live-attenuated varicella vaccine (LAVV) designed to prevent primary varicella in varicella zoster seronegative individuals are permissible post HCT and only in select patient groups. All other vaccines, including the shingles vaccines, are contraindicated post HCT. Current data, primarily in pediatric HCT recipients, demonstrate a 60-70% response following a single MMR or LAVV. A two-dose schedule increases the seroconversion rate following these vaccines. This review will highlight published studies on the immunogenicity of MMR and the LAVV, areas in which data on these vaccines are lacking, the criteria for their use in patients transplanted at our center and potential studies to answer questions posed by the growing number of transplant survivors and their physicians on how to safely administer live-attenuated viral vaccines.