Safety and efficacy of early vaccination with live attenuated measles vaccine for hematopoietic stem cell transplant recipients and solid organ transplant recipients

Vaccination with the live attenuated measles vaccine is currently recommended two years after hematopoietic stem cell transplantation (HSCT) and generally contraindicated after solid organ transplantation (SOT) due to safety concerns.However, in the last few years new data on the administration of the measles vaccine to HSCT recipients less two years post-transplantation and to SOT recipients have become available.This new data may change current guidelines and practices. The objective of this review is to provide an overview of the current data on the safety and efficacy of early measles vaccination for HSCT- and SOT recipients.PubMed and EMBASE were searched from the earliest date available through October 2019 to identify all research that reported on the safety and efficacy of measles vaccination after SOT or less than two years after HSCT.A total of ten studies was included in this review. In the six studies that evaluated the efficacy of measles vaccination after SOT, seroconversion rates ranged from 41 to 100% after one dose and 73 to 100% after two doses. In the four studies that evaluated the efficacy of measles vaccination less than two years after HSCT, seroconversion rates ranged from 33 to 100% after one dose and 100% after two doses. In all studies, the administration of the measles vaccine after transplantation was considered to be safe. There were no cases of infection with the attenuated vaccine strain, and there were no adverse events related to the vaccination.Data on the administration of the measles vaccine after SOT and less than two years after HSCT is scarce. However, the current data available suggest that it is efficacious and well tolerable. Therefore, early measles vaccination could be considered in selected groups of SOT- and HSCT recipients during increased measles transmission or an outbreak setting.