ABSTRACT
Background: In April 2020, the Mayo Clinic helped establish the US Food and Drug Administration Expanded Access Protocol for COVID-19 (coronavirus disease 2019) convalescent plasma (CCP). The effectiveness of CCP in the published literature is contradictory because some retrospective studies showed benefit in reducing mortality and severe illness, whereas prospective randomized controlled trials demonstrated no benefit of CCP. Objectives: To discuss (1) the implementation of CCP across Kaiser Permanente Southern California between April 2020 and April 2021, (2) retrospective multivariable analysis of 2,831 patients with COVID-19 who were transfused with CCP compared with 18,475 patients with COVID-19 who did not receive CCP, (3) how to reconcile contradictory published data regarding the efficacy of CCP, and (4) guidance regarding the future use of convalescent plasma in a large community hospital setting. Methods: Multivariable analysis was controlled for demographic characteristics, level of oxygen delivery, intensive care unit stay, selected laboratory findings, and other concurrent treatment-related variables. Tubing segments from 151 CCP units transfused between October 2020 and April 2021 were retrospectively tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) anti-spike protein receptor-binding domain IgG. Multivariable analysis showed that CCP transfusion did not affect mortality rates at 30 days and 5 months (odds ratio, 1.04, 95% CI, 0.87-1.25, and hazard ratio, 1.05, 95% CI, 0.93-1.19). Conclusions: If convalescent plasma is offered as a therapeutic in a future viral pandemic, we recommend (1) transfusing only those patients who are negative for neutralizing antibodies, (2) transfusing very early during the disease course, (3) only using convalescent plasma with known levels of neutralizing antibodies, or (4) alternatively providing fractionated hyperimmune globulin.