Convalescent Plasma Reduces COVID-19 Hospitalizations Nearly 50%

Convalescent plasma from patients who have recovered from COVID-19 reduced hospitalizations by nearly 50% for outpatients infected with the virus in a nationwide, multicenter clinical trial.

Johns Hopkins Medicine and the Johns Hopkins Bloomberg School of Public Health led the clinical trial between June 2020 and October 2021. Researchers administered one dose of either polyclonal high-titer convalescent plasma or placebo to 1,181 patients.

All patients were 18 years of age and older and tested positive for COVID-19 within eight days prior to transfusion.

The study found that 17 patients (2.9 percent) who received the convalescent plasma required hospitalization within 28 days of their infusion, compared to 37 (6.3 percent) who received placebo.

These study outcomes translate to a relative risk reduction for hospitalization of 54 percent.

“This is another effective treatment for COVID-19 with the advantages being low cost, wide availability and rapid resilience to the evolving SARS-CoV-2,” Kelly Gebo, MD, MPH, professor of medicine at the Johns Hopkins University School of Medicine and the study’s co-lead author, said in the announcement.

“We believe that the best role for COVID-19 high-titer convalescent plasma is extending its use to early outpatient treatment when other therapies, such as monoclonal antibodies or drugs, are either not readily available — as in low- and middle-income countries — or ineffective — as with SARS-CoV-2 variants that are resistant to certain monoclonal antibodies,” Gebo continued.

Convalescent plasma is the only antibody therapy effective against various COVID-19 variants, including the delta and omicron strains currently spreading globally.

In August 2020, FDA authorized convalescent plasma as a COVID-19 treatment in hospitalized patients after data showed that the known potential benefits of convalescent plasma outweighed the known potential risks.

Before the plasma can be considered an early COVID-19 treatment option, FDA must expand the current authorization to include its use.

Johns Hopkins Medicine shared its findings with FDA and the World Health Organization and hope that both organizations see the value of convalescent plasma for outpatients based on the study’s outcomes.

Baylor College of Medicine, Georgetown University School of Medicine, Mayo Clinic, MedStar Washington Hospital Center, National Institutes of Health, and the University of California Irvine College of Medicine were just a few of the 25 institutions and organizations that participated in the study.