Convalescent plasma may help halt the coronavirus, but it is restricted by WHO and the CDC.
A study from Johns Hopkins University has found that that convalescent plasma can reduce coronavirus, including Omicron, hospital admissions by more than half (54%) if therapy is administered “within eight days” of the first signs of symptoms. The findings were published as a preprint study on medRxiv, which has yet to be peer-reviewed.
This multicenter, double-blind randomized controlled trial compared the efficacy and safety of “SARS-CoV-2 high titer convalescent plasma to placebo control plasma in symptomatic adults >18 years positive for SARS-CoV-2 regardless of risk factors for disease progression or vaccine status.” The authors recruited 1181 adults from June 3, 2020, to October 1, 2021. Those who chose to participate were randomly assigned to the high-titer convalescent plasma or a placebo, and the team found that “2.9% of people receiving the therapy were hospitalized compared to 6.3% who received placebo control plasma.”
The authors conclude in the pre-print, “Early administration of high titer SARS-CoV-2 convalescent plasma reduced outpatient hospitalizations by more than 50%. High titer convalescent plasma is an effective early outpatient COVID-19 treatment with the advantages of low cost, wide availability, and rapid resilience to variant emergence from viral genetic drift in the face of a changing pandemic.”
“We have a clear difference,” principal investigator David Sullivan, MD, a professor at Johns Hopkins Bloomberg School of Public Health in Baltimore, said. “We think that plasma with high levels of antibodies can adapt faster to Omicron, although it will take us longer to get an Omicron-specific supply.”
Arturo Casadevall, MD, chair of the Department of Molecular Microbiology and Immunology at Johns Hopkins added, “This is very good news since we are in the midst of the Omicron surge, which has defeated [some of] our major monocular antibody therapies. So, we have a new tool to keep people from progressing in their disease and to reduce progression or hospitalization.”
“Whereas many convalescent plasma studies were done in hospitalized patients, this is one of only a handful performed in outpatients,” the researchers note.
However, the Food and Drug Administration (FDA) restricted emergency use authorization (EUA) for convalescent plasma in February 2021 to include only high-dose titer plasma and to limit the therapy to hospitalized patients with early disease or for immunocompromised patients. The research team would like to see the FDA relax these restrictions.
“We have shared this data with both the World Health Organization (WHO) and the FDA,” explained study co-author Kelly Gebo, MD, MPH, professor of medicine at Johns Hopkins University School of Medicine. “We do believe that this could be scaled up quickly. Convalescent plasma could be used as a potential treatment as variants continue to evolve, such as we’ve seen with Omicron.”
Just a few weeks ago, WHO updated its guideline on COVID-19 therapies, too, recommending against the use of convalescent plasma for non-severe COVID-19 patients and indicating “it should only be used within clinical trials for severe and critical COVID-19 patients.” The organization reported, “Current evidence shows that convalescent plasma does not improve survival or reduce the need for mechanical ventilation, while it has significant costs.”