Safety and efficacy of convalescent plasma for severe COVID-19: a randomized, single blinded, parallel, controlled clinical study
Authors: Rojas Manuel , Rodríguez Yhojan , Hernández Juan Carlos , Díaz-Coronado Juan C. , Vergara José Alejandro Daza , Vélez Verónica Posada , Mancilla Jessica Porras , Araujo Iván , Yepes Jairo Torres , Ricaurte Oscar Briceño , Pardo-Oviedo Juan Mauricio , Monsalve Diana M. , Acosta-Ampudia Yeny , Ramírez-Santana Carolina , García Paula Gaviria , Landinez Lina Acevedo , Correales Luisa Duarte , Grass Jeser Santiago , Pérez Cristian Ricaurte , López Gustavo Salguero , Mateus Nataly , Mancera Laura , Devia Ronald Rengifo , Orjuela Juan Esteban , Parra-Moreno Christian R. , Buitrago Andrés Alfonso , Ordoñez Inés Elvira , Osorio Claudia Fabra , Ballesteros Nathalia , Patiño Luz H. , Castañeda Sergio , Muñoz Marina , Ramírez Juan David , Bastard Paul , Gervais Adrian , Bizien Lucy , Casanova Jean-Laurent , Camacho Bernardo , Gallo Juan Esteban , Gómez Oscar , Rojas-Villarraga Adriana , Pérez Carlos E. , Manrique Rubén , Mantilla Rubén D. , Anaya Juan-Manuel 
Published: June 2022

Abstract
Background
Convalescent plasma (CP) has been widely used to treat COVID-19 and is under study. However, the variability in the current clinical trials has averted its wide use in the current pandemic. We aimed to evaluate the safety and efficacy of CP in severe coronavirus disease 2019 (COVID-19) in the early stages of the disease.

Methods
A randomized controlled clinical study was conducted on 101 patients admitted to the hospital with confirmed severe COVID-19. Most participants had less than 14 days from symptoms onset and less than seven days from hospitalization. Fifty patients were assigned to receive CP plus standard therapy (ST), and 51 were assigned to receive ST alone. Participants in the CP arm received two doses of 250 mL each, transfused 24 h apart. All transfused plasma was obtained from "super donors" that fulfilled the following criteria: titers of anti-SARS-CoV-2 S1 IgG ≥ 1:3200 and IgA ≥ 1:800 antibodies. The effect of transfused anti-IFN antibodies and the SARS-CoV-2 variants at the entry of the study on the overall CP efficacy was evaluated. The primary outcomes were the reduction in viral load and the increase in IgG and IgA antibodies at 28 days of follow-up. The per-protocol analysis included 91 patients.

Results
An early but transient increase in IgG anti-S1-SARS-CoV-2 antibody levels at day 4 post-transfusion was observed (Estimated difference [ED], − 1.36; 95% CI, − 2.33 to − 0.39; P = 0.04). However, CP was not associated with viral load reduction in any of the points evaluated. Analysis of secondary outcomes revealed that those patients in the CP arm disclosed a shorter time to discharge (ED adjusted for mortality, 3.1 days; 95% CI, 0.20 to 5.94; P = 0.0361) or a reduction of 2 points on the WHO scale when compared with the ST group (HR adjusted for mortality, 1.6; 95% CI, 1.03 to 2.5; P = 0.0376). There were no benefits from CP on the rates of intensive care unit admission (HR, 0.82; 95% CI, 0.35 to 1.9; P = 0.6399), mechanical ventilation (HR, 0.66; 95% CI, 0.25 to 1.7; P = 0.4039), or mortality (HR, 3.2; 95% CI, 0.64 to 16; P = 0.1584). Anti-IFN antibodies and SARS-CoV-2 variants did not influence these results.

Conclusion
CP was not associated with viral load reduction, despite the early increase in IgG anti-SARS-CoV-2 antibodies. However, CP is safe and could be a therapeutic option to reduce the hospital length of stay.
Trial registration NCT04332835