Breakthrough COVID-19 after SARS-CoV-2 vaccination in solid organ transplant recipients: An analysis of symptomatic cases and monoclonal antibody therapy

Background Solid organ transplant (SOT) recipients are at increased risk for complications from SARS-CoV-2 infection. Little is known regarding clinical course and outcomes of breakthrough COVID-19 in the fully vaccinated SOT population. We sought to describe our cohort of SOT recipients who developed symptomatic breakthrough COVID-19 after full vaccination. Methods We conducted a retrospective review of SOT recipients diagnosed with COVID-19 at least 14 days after completing SARS-CoV-2 vaccination. Patients were analyzed according to those presenting with mild-to-moderate and severe COVID-19, respectively. We described presenting characteristics, COVID-19 therapy, and analyzed outcomes including emergency department (ED) visits, hospitalization, and intensive care unit (ICU) admission. Results Thirty-five patients met inclusion criteria. These had a mean age of 60.8 years and kidney transplant was the most common SOT type. Five patients presented with severe COVID-19 at diagnosis, all requiring hospitalization without ICU admission. From the 30 patients who presented with mild-to-moderate infection, 28 received casirivimab-imdevimab. Four of these 28 (14.3%) had an ED visit, with one requiring hospital admission (3.4%). No patients required ICU admission. Conclusion Breakthrough COVID-19 may occur in SOT recipients after full vaccination, though they appear to have acceptable outcomes. Anti-spike monoclonal antibody therapy for eligible SOT patients may have mitigated clinical progression and improved the outcomes. Further study with large cohorts is warranted.