Early mortality benefit with COVID-19 convalescent plasma: a matched control study

Convalescent plasma can provide passive immunity during viral outbreaks, but the benefit is uncertain for the treatment of novel coronavirus disease 2019 (COVID-19). Our goal is to assess the efficacy of COVID-19 convalescent plasma (CCP). In all, 526 hospitalized patients with laboratory-confirmed SARS-CoV-2 at an academic health system were analyzed. Among them, 263 patients received CCP and were compared to 263 matched controls with standard treatment. The primary outcome was 28-day mortality with a subanalysis at 7 and 14 days. No statistical difference in 28-day mortality was seen in CCP cases (25·5%) compared to controls (27%, P = 0·06). Seven-day mortality was statistically better for CCP cases (9·1%) than controls (19·8%, P < 0·001) and continued at 14 days (14·8% vs. 23·6%, P = 0·01). After 72 h, CCP transfusion resulted in transitioning from nasal cannula to room air (median 4 days vs. 1 day, P = 0·02). The length of stay was longer in CCP cases than controls (14·3 days vs. 11·4 days, P < 0·001). Patients with COVID-19 who received CCP had a decreased risk of death at 7 and 14 days, but not 28 days after transfusion. To date, this is the largest study demonstrating a mortality benefit for the use of CCP in patients with COVID-19 compared to matched controls.