COVID-19 Convalescent Plasma in 20,000 Hospitalized Patients

Antibodies Protect Against COVID-19At the beginning of the COVID-19 pandemic, physicians did all they could to treat hospitalized patients without knowing much about the virus and treatments in the evolution phase. Taking place from April 3 to August 31, 2020, the United States Federal Drug Administration (FDA)/ BARDA- funded Convalescent Plasma Program for COVID-19 led by Mayo Clinic examined the safety and efficacy of convalescent plasma therapy, which transfuses plasma from patients who have recovered from COVID-19 in hopes that their newly developed anti-viral antibodies and other bioactive elements could help those fighting the virus in the hospital. This study was conducted by Mayo Clinic. To help explain the program and its outcomes, Myocarditis Foundation takes a closer look at the findings here.

Objective and Methods of the Study

The Mayo Clinic-led Convalescent Plasma Program for COVID-19 first provided access to convalescent plasma across the United States and transfused around 95,000 patients with plasma. Because data were lacking, they sought to provide data about the safety and efficacy of convalescent plasma as a viable therapeutic for hospitalized patients with severe or life-threatening COVID-19. Their initial report found that convalescent plasma was safe in a sample of 5,000 patients, and a subsequent report confirmed safety in over 20,000 hospitalized COVID-19 patients.

According to Mayo Clinic, the following methods were used for the study:

  • The study hypothesized that “both the seven-day mortality rate and the number of serious adverse events related to the transfusion of convalescent plasma would continue to be low.”
  • It also hypothesized that more critically ill patients would show higher rates of mortality.
  • Over 20,000 patients received COVID-19 convalescent plasma transfusions from donors who had survived the virus, with consent granted from the patient or their legally authorized representative. The transfusions were administered intravenously at regular time intervals and contained between 200 and 500 mL of convalescent plasma.
  • Eligible patients met the following criteria:
    • 18 years of age or older
    • Hospitalized after a laboratory-confirmed COVID-19 diagnosis
    • Had severe or life-threatening COVID-19 or was deemed “by a healthcare provider to be at high risk of progression” to severe or life-threatening illness
  • REDCap data collection forms reported each serious adverse event (SAE) that occurred over the study.

The Findings

The study found that “the incidence of all serious adverse events was low,” with any thromboembolic, thrombotic, and cardiac events occurring in these patients after the transfusion being deemed unrelated to the convalescent plasma “per se.” Further, the seven-day mortality rate in extremely high-risk patients treated with convalescent plasma was 8.6%, which was similar or less than reports of mortality without treatment with convalescent plasma showing what Mayo Clinic calls “continued optimism for the safety of COVID-19 convalescent plasma.” Another publication from the study, using a subset of around 3,000 COVID-19 patients, found that plasma with higher anti-viral antibody levels reduced mortality, indicating its efficacy as a treatment.

Learn More from Myocarditis Foundation

Safety data provided by this study, and others, were used by the FDA to transition convalescent plasma from an “Expanded Access Program” to an “Emergency Use Authorization” which it currently holds. As this study reported critical safety and efficacy data on the use of COVID-19 convalescent plasma, it also raised awareness of the need for donors. If you or a loved one has recovered from COVID-19 and would like to support the recovery of those in critically ill or life-threatening condition, find information from the FDA on where to make a donation near you.

As more information becomes known about COVID-19, the Myocarditis Foundation is keeping abreast of the latest developments pertaining to the virus’ link to heart disease and myocarditis. To learn more, contact Myocarditis Foundation today, or support our mission by making a donation now.