A Retrospective Review of Revaccination Patterns in Pediatric Hematopoietic Stem Cell Transplantation Recipients.

After a hematopoietic stem cell transplantation (HSCT), patients are left with little to no immunity to prevent infections. Importantly, this includes immunity gained from previous exposures, including vaccinations. This loss of immunity is a direct result of previous chemotherapy, radiation, and conditioning regimens the patients receive. It is critical to revaccinate patients post-HSCT to ensure protective immunity against vaccine-preventable diseases. Before 2017, all patients at our institution were referred to their pediatrician at approximately 12-month post-HSCT to be revaccinated. Clinical concern was raised at our institution regarding nonadherence and errors in vaccine schedules. To understand the magnitude of the problem with revaccination, we performed an internal audit of post-vaccine adherence in patients who received an HSCT between 2015 and 2017. A multidisciplinary team was developed to review the audit results and make recommendations. This audit revealed delays in the initiation of the vaccine schedule, incomplete adherence to the recommended revaccination schedule, and errors in administration. Based on the review of the data, the multidisciplinary team recommended an approach for systematic assessment of vaccine readiness and centralization of the administration of vaccines to be done within the stem cell transplant outpatient center.