Jose F. Camargo

Background The optimal number of doses as well as the role for measurement of postvaccination titers after measles, mumps, rubella (MMR) vaccination in adult hematopoietic cell transplantation (HCT) recipients remains unknown. Methods In the present study, we assessed humoral immunity against measles, mumps and rubella before and after MMR vaccination in 187 adults who received at least one dose of the MMR vaccine after HCT. Results Among those with baseline titers, posttransplant prevaccination seroprotection rates were 56%, 30%, and 54% for measles, mumps, and rubella, respectively; and significantly lower in allogeneic versus autologous HCT recipients for measles (39% vs. 80%, p = .0001), mumps (22% vs. 41%; p = .02) and rubella (48% vs. 62%, p = .12). Among those who were seronegative at baseline, seroconversion rates after one dose of MMR were 69%, 56%, and 97% for measles, mumps, and rubella, respectively. Seronegative patients after one dose of MMR (i.e., nonresponders) seroconverted for measles and mumps after a second MMR vaccine dose. Conclusion Our findings demonstrate successful restoration of protective immunity against measles, mumps, and rubella after vaccination in adult HCT recipients; one dose of MMR elicited protective titers in the majority of patients, and a second vaccine dose was immunogenic in nonresponders. image