Up‐to‐date Status of Childhood Immunizations at the Time of Transplant Among Pediatric Solid Organ Transplant Recipients

INTRODUCTION: The purpose of our study was to assess UTD status of routine childhood vaccinations at the time of organ transplant among our institution's pediatric SOT recipients and assess the reasons behind underimmunization. MATERIALS AND METHODS: We reviewed vaccination records of pediatric recipients of heart, kidney, and liver transplants at Mayo Clinic, Rochester, MN who received a transplant between January 2011 and December 2024. All immunizations received prior to date of transplantation were included. Once immunization status was determined, the EMR was further reviewed to assess reasons why patients were not UTD. RESULTS: A total of 204 patients were included in the study after meeting inclusion criteria: 68 kidney, 80 heart, and 55 liver transplant recipients; one patient received both a liver and kidney transplant. Seventy-seven patients (37.7%) were UTD at the time of SOT. When excluding live vaccines, 90 patients (44.1%) were UTD. The series most commonly not UTD was HPV (59 patients not UTD, 28.9%); the most UTD series was pneumococcal vaccine (six patients not UTD, 2.9%). Among 127 patients not UTD, 30 (23.6%) patients were not UTD due to time-based factors, followed by 27 (21.3%) due to patient-based factors, 25 (19.7%) due to provider-based, 14 (11%) due to medically contraindicated, and 14 (11%) due to hospital policy factors. Seventeen patients (13.4%) were classified as multi-category. CONCLUSIONS: Less than 40% of pediatric SOT recipients were UTD on routine immunizations at time of transplant. This was due to a variety of factors. Strategies to increase uptake of immunizations prior to transplant among this vulnerable group should be further explored.