COVID-19 Mortality in Vaccinated vs. Unvaccinated Liver & Kidney Transplant Recipients: A Single-Center United States Propensity Score Matching Study on Historical Data

Abstract

Introduction: Existing studies report variable impact of vaccination on Coronavirus Disease (COVID-19) morbidity and mortality in solid organ transplant (SOT) recipients. This study aimed to perform a propensity score matching (PSM) analysis on COVID-19 survival of vaccinated and unvaccinated SOT patients who contracted the disease at a single US academic transplant center. Methods: All consecutive COVID-19 positive cases on adult liver, kidney or combined liver-kidney recipients were identified and demographics, comorbidities, immunosuppression, COVID-19 treatment and hospitalization status, COVID-19 vaccination status, and early mortality recorded. PSM study was performed on age and sex for completed vaccination status at time of infection, followed by multivariable analysis and survival curve plotting. Results: 144 SOT patients were diagnosed with COVID-19, with 98 unvaccinated. PSM reduced study number to 101. Matched data multivariable analysis for 60-day mortality identified age and post-kidney transplant status to significantly increase 60-day mortality odds (OR 1.22, p < 0.001 and OR 40.93, p < 0.001, respectively). Kaplan–Meier analysis showed inferior post-infection survival in the unvaccinated group [(30 days; vaccinated vs. unvaccinated 97.8% vs. 89.1%, respectively; p = 0.089) (60 days; 97.8% vs. 83.6%, respectively; p = 0.019)]. Conclusions: Matched data survival analysis demonstrated inferior survival in the unvaccinated group, supporting COVID-19 vaccination in SOT recipients.