1396. Live Virus Vaccination Following Pediatric Liver Transplantation: Results from Two Academic Children’s Hospitals

BACKGROUND: Guidelines for immunization following solid organ transplantation discourage live virus vaccination (LVV) in most recipients. Single-center studies support LVV as safe and effective in orthotopic liver transplant (OLT) recipients on steroid-free immunosuppression (IS). We retrospectively evaluated LVV after OLT at 2 pediatric hospitals. METHODS: Records from OLT recipients between Jan 2007 and Dec 2017 at Lurie Children’s (Chicago) and Children’s Hospital of Philadelphia were reviewed. Patients who underwent OLT at either institution, had ≥ 2 years of follow up, and had documentation of vaccination prior to OLT were included. Adverse events (AEs) within two weeks of receipt of LVV were captured. Factors that might influence the selection of patients for LVV were reviewed, including choice, dose, frequency, and levels of IS medications. IS in non-vaccinated patients was compared to vaccinated patients at two year post-transplant follow-up in both groups using Chi-Square and T-test. RESULTS: Data from 249 patients met inclusion criteria. Varicella zoster (VZV) vaccine was given at least once to 92 patients post-transplant, and MMR to 91 (Table 1). Compared to patients who were re-vaccinated after transplant, those who received their first LVV after OLT were transplanted at a younger age (0.8 v 2.2 years) and received LVV sooner post-OLT (649 v 907 days). AEs were rare for either LVV: 2 experienced injection site reaction, 2 localized rash, and 1 had fever. One recipient experienced worsening rejection one month after MMR and received IV steroids and increased IS, but had no clinical findings concerning for viral infection from vaccination. Most LVV recipients were on a single IS agent both at time of LVV and 2 year post-OLT (Table 2), with tacrolimus the most frequent agent. Compared to those that did not received LVV post-OLT, those that did were on one IS agent more often. Tacrolimus levels were similar among patients receiving LVV post-OLT compared with those who did not. Table 1 [Image: see text] Table 2 [Image: see text] CONCLUSION: In a series of pediatric OLT recipients, post-OLT LVV was generally safe and well tolerated. Patients who received LVV post-OLT were more often on one IS agent at 2 year follow up compared to those who did not. Our study supports prospective efforts to define guidelines for patients who may safely receive LVV after OLT. DISCLOSURES: Kevin J. Downes, MD, Merck, Inc. (Grant/Research Support)