Convalescent Plasma Improves COVID-19 Survival Rates

A new study suggests that using plasma from convalescent COVID-19 patients is safe, effective, and improves the chances of survival among those who are severely ill.

Researchers at the Mayo Clinic (Rochester, MN, USA), Michigan State University (MSU; East Lansing, USA), and other institutions conducted a study involving 20,000 patients over the age of 18 years who were confirmed with SARS-CoV-2 infection. The patients were administered ABO compatible convalescent plasma donated by recently-recovered COVID-19 survivors. The treatment involved intravenous administration of 200-500 ml of convalescent plasma. Patients were assessed for improvement at four hours and seven-days after the transfusion of the plasma.

The results revealed that the incidence of all serious adverse events was low; these included transfusion reactions, thromboembolic or thrombotic events (both less than 1%), and cardiac events (3%), which were mostly judged to be unrelated to the plasma transfusion per se. Seven-day mortality was 8.6%, and was higher among more critically-ill patients, including those admitted to the intensive care unit (ICU) 10.5%), the mechanically ventilated (12.1%), and those with septic shock or multiple organ dysfunction or failure (14%). The study was published in on June 20, 2002, in Mayo Clinical Proceedings.

“It is remarkable that there was no system in place for convalescent plasma use in March 2020, and yet within months, the nation is now able to meet most of the demand, despite complex logistics,” concluded lead author Michael Joyner, MD, of the Mayo Clinic, and colleagues. “These updated data provide robust evidence that transfusion of convalescent plasma is safe in hospitalized patients with COVID-19, and support the notion that earlier administration of plasma within the clinical course of COVID-19 is more likely to reduce mortality.”

The use of convalescent plasma is an interim approach until availability of hyperimmune globulin, drug therapies, and vaccines, as the vast majority of patients who recover from COVID-19 develop some level of neutralizing antibodies to SARS-CoV-2 proteins 2-3 weeks following infection. Collecting convalescent plasma from previously infected individuals to passively-transfer antibodies in order to protect or treat human beings dates back almost 100 years, with some evidence for benefit against rabies, hepatitis B, polio, measles, influenza, Ebola and other pathogens.

Related Links:
Mayo Clinic
Michigan State University