Abstract
To ascertain the current state of vaccination for pediatric patients after allogeneic hematopoietic stem cell transplantation, a questionnaire was distributed to all 99 participating hospitals of the Japan Association of Childhood Leukemia Study (JACLS). Sixty-six of the 99 hospitals (66.7%) surveyed responded. Fifteen of 44 hospitals (34.1%) reported having established vaccination guidelines including Centers for Disease Control and Prevention (CDC) and European Group for Blood and Marrow Transplantation (EBMT) guidelines. Rates of vaccine coverage in patients without receiving immunosuppressants was 86.8% for inactive and toxoid vaccines and 86.8% for live vaccines, while those in patients receiving a low dose of immunosuppressants is 30.2% for inactive and toxoid vaccinesand 11.3% for live vaccines, respectively. More than half of the hospitals applied some assays of immunological reconstitution for the start of vaccination. In some hospitals, varicella and polio vaccinations were performed even for patients receiving a low dose of immunosuppressants. Furthermore, live vaccines were given 6 or 12 months after transplantation in most of the hospitals without any adverse effects. Prospective studies are required to evaluate the utilityof immunologic reconstitution assays for assessing the safety and efficacy of vaccination at an early stage after transplantation.
