484. Clinical Description of SARS-CoV-2 Infection in Patients with Primary Antibody Deficiency Who Received Tixagevimab/Cilgavimab Prophylaxis

BACKGROUND: Patients with primary antibody deficiency are known to be associated with a higher risk of SARS-CoV-2 infection, complications, and mortality. Tixagevimab/Cilgavimab prophylaxis has shown efficacy in reducing hospitalization and mortality. We aim to describe the clinical characteristics and outcomes of COVID-19 cases in primary antibody deficiency patients receiving tixagevimab/cilgavimab prophylaxis in South Korea. METHODS: This is a descriptive analysis of COVID-19 infection in primary antibody deficiency patients at Severance Children's Hospital. From September 2021 to February 2023, we retrospectively collected data, including demographic characteristics, comorbidities, tixagevimab/cilgavimab prophylaxis status, SARS-CoV-2 vaccination, COVID-19 infection, clinical presentation, COVID-19 treatment, oxygen supplement, hospitalization, and clinical outcome. RESULTS: Thirteen patients (12 with X-linked agammaglobulinemia and 1 with common variable immunodeficiency) were enrolled in this study. Among them, 10 received tixagevimab/cilgavimab prophylaxis, while the remaining 3 did not. Three patients developed breakthrough infection after receiving prophylaxis. Patient 1 (29 years old, male) completed a SARS-CoV-2 booster mRNA vaccination, had no prior COVID-19 infection, and developed COVID-19 infection 104 days after prophylaxis. Patient 2 (33 years old, male) received 2 doses of mRNA vaccine, had no prior infection history, and developed COVID-19 infection 3 days after prophylaxis. Patient 3 (13 years old, male) had no history of previous vaccination, had an infection history before receiving prophylaxis, and developed COVID-19 infection 19 days after prophylaxis. All 3 patients experienced mild symptoms and did not require oxygen therapy or hospitalization. Of the 7 patients who were not infected with COVID-19 after prophylaxis, 6 had a history of COVID-19 infection, and all of them received SARS-CoV-2 mRNA vaccine. The follow-up period after prophylaxis ranged from 198 to 241 days. [Figure: see text] CONCLUSION: In this study, we observed that 3 out of 10 primary antibody deficiency patients who received tixagevimab/cilgavimab prophylaxis were infected COVID-19 but did not require hospitalization or oxygen supplementation. DISCLOSURES: All Authors: No reported disclosures