Bags of plasma

According to a national study, antibody-rich plasma from patients who recovered from COVID-19 can be an effective tool in early treatment of COVID-19.

April 8, 2022

Antibody-rich convalescent plasma from patients who have recovered from COVID-19 may be an effective tool in early treatment of COVID-19 and can reduce the risk of hospitalization in newly diagnosed patients by more than 50%, according to a multicenter clinical trial in which ARUP Laboratories participated.

The findings suggest COVID-19 convalescent plasma (CCP) is a viable, safe, and effective early treatment tool for COVID-19. Researchers, including scientists from ARUP, propose that CCP may be beneficial as part of a cache of treatment options for patients who test positive for SARS-CoV-2, the virus that causes COVID-19.

The complete findings from the study are published in the March 30, 2022, New England Journal of Medicine article, “Early Outpatient Treatment for COVID-19 with Convalescent Plasma.” Researchers from Johns Hopkins Medicine and the Johns Hopkins Bloomberg School of Public Health led the multistate, multicenter, double-blind, randomized controlled trial.

ARUP was among a handful of blood centers that contributed plasma containing SARS-CoV-2 antibodies—provided by donors that had recovered from COVID-19—to the trial. In conjunction with University of Utah Health, ARUP began collecting convalescent plasma in May 2020 in anticipation of formal, randomized clinical trials of the safety and efficacy of CCP as a treatment for COVID-19, and ARUP joined the Johns Hopkins study in September 2020.

Convalescent plasma has been used to treat diseases for nearly 100 years, but it had not yet been studied rigorously because data from randomized controlled trials were lacking, said Ryan Metcalf, MD, CQA(ASQ), section chief of Transfusion Medicine at the University of Utah Health and ARUP Laboratories.

Using apheresis technology, which can centrifuge the blood during collection to remove only the plasma, ARUP was able to make an important contribution to a well-designed study that has direct implications for practice and patient care, he said.

“This study provides important evidence suggesting a benefit of CCP over plasma placebo in the outpatient setting, although the number needed to treat was about 30,” Metcalf said. “While data from prior studies provided some information, this study gives us more evidence that there likely is some efficacy due to its design and larger sample size.”

The study was conducted between June 2020 and October 2021 and randomly treated 1,180 patients with either placebo plasma or plasma from donors who had recovered from COVID-19. Study participants were between the ages of 18 and 84, and a majority were unvaccinated against COVID-19. All participants received transfusions of plasma, either placebo or CCP, within nine days of a positive test for SARS-CoV-2.

In all, 592 patients received CCP, and of those, just 17 (2.9%) required hospitalization. Among the 589 participants who received placebo plasma, 37 (6.9%) were hospitalized within a month of the transfusion.

Overall, the use of CCP reduced the relative risk of hospitalization in patients by 54%; however, the absolute risk reduction was only a few percentage points due to the overall low hospitalization rate in the study. 

Researchers said the trial’s findings have public health implications in areas of the world where resource constraints may limit vaccine availability or access to other, more costly treatment options, such as monoclonal antibodies. The findings also support that convalescent plasma should be investigated as a treatment during future pandemics while monoclonal therapies and vaccines are being developed.


Jennifer Dobner,