Mayo Clinic Led Emergency Use Access National Program Reveals Convalescent Plasma Safe & Possible

Mayo Clinic Led Emergency Use Access National Program Reveals Convalescent Plasma Safe & Possible

The national convalescent plasma study led by Mayo Clinic and made possible as a U.S. Food and Drug Administration Expanded Access Program for COVID-19, created a lot of interest across the United States. TrialSite News received hundreds of emails from interested physicians and patients. In large numbers, physicians that don’t undertake research sought out to get involved with this study—to become investigators to help contribute to the battle against COVID-19: the worst public health crisis in modern times. The results from this important study are now available: Mayo Clinic researchers and collaborators found investigational plasma to be safe following transfusion in a diverse group of 20,000 patients. The investigators report that they don’t have sufficient amounts of data yet to make any claims that convalescent plasma effectively treats COVID-19—although there are some promising data points—more research ongoing will contribute to the final answer.


Recently reported in Mayo Clinic Proceedings, the safety report assessed the seven days following the transfusion for hospitalized patients between April 3 and June 11 who were deemed at risk of progressing to a severe or life-threatening condition. The study team did a phenomenal job ensuring a diverse patient participation: 40% of the patients were women; 20% African Americans; nearly 35% Hispanic; and 5% Asian. Seven-day mortality rates declined to 8.6% compared to 12% in a previous safety study of the first 5,000 transfused patients. Serious adverse events continued to be less than one percent.

A Catalyst for Doctors to Investigator

TrialSite News actually served as one of many informal clearinghouses for this national initiative—helping to direct many physicians interested in participating to the convalescent plasma initiative website. Upon writing about the effort, many dozens of doctors emailed TrialSite News to ask how they could participate in the Emergency Access Program.  The TrialSite News staff was highly encouraged by the large showing of physician interest in the national convalescent plasma initiative. Only about 3% of the total physician population participate in research, so serving as investigators has traditionally represented a barrier to more research in the United States. With the advent of COVID-19, a newfound interest in research emerged.  Dr. Joyner and team should be commended for designing, organizing, and leading what has been a truly notable research initiative.

Engaged Investigators & Diverse Subject Participation

Researcher DeLisa Fairweather, PhD, discussed the exceptional aspects of this study, noting, “The 7000-plus physicians who are part of the program have done an exceptional job of offering convalescent plasma to a diverse group of patients enrolling women as forty percent of the participants as well as a significant number of patients who are African American, Asian or Hispanic ethnicity.” Fairweather continued, “We hope recruitment of minority subjects continues to increase given the disproportionate burden these communities have faced with COVID-19.”

Safe but Not a Proven Treatment for COVID-19

The expanded safety report reveals a decline in mortality, which appears contemporary with the rapid availability of plasma for use, but the authors caution that this alone doesn’t offer evidence on the effectiveness of plasma for treating COVID-19. Given the accelerating use of the therapy, research is now broadening its focus to assess indicators of efficacy. Presently, convalescent plasma therapy is the only antibody-based therapy for COVID-19.

Michael Joyner, MD, principal investigator of the Emergency Access Program at May Clinic and lead author of the article, commented, “Our efforts to understand convalescent plasma continue.” Dr. Joyner noted, “We’re optimistic but must remain objective as we assess increasing amounts of data.”

Some Evidence of Efficacy But Not Enough Data

Thus far, the researchers report that the mortality rate decreased while the patients in the latter part of this study were less critically ill. However, the decrease could also be in part due to improved medical care based on increased knowledge during the pandemic and that more of the patients received the plasma earlier in their hospital treatment.  In March, there was no system in place for delivering convalescent plasma but now there is sufficient donation needs to meet most of the demand. As more donors came forward more rapidly, it was more likely their plasma contained neutralizing antibodies.


The study was supported by a contract with the U.S. Health and Human Services, Biomedical Advanced Research and Development Authority; multiple grants from the National Institutes of Health; Natural Sciences and Engineering Research Council of Canada; the Schwab Charitable Fund; United Health Group; the National Basketball Association; Millennium Pharmaceuticals; Octapharma USA, Inc.; and Mayo Clinic.

Lead Research/Investigatory Centers

The convalescent plasma program at Mayo Clinic grew from a national initiative of physicians and investigators from 10 institutions that self-organized to investigate the use of convalescent plasma during the COVID-19 pandemic. These institutions include Mayo Clinic, Johns Hopkins University, Washington University, Einstein Medical Center, Icahn School of Medicine at Mount Sinai, Michigan State University, and many other academic medical centers and government agencies seeking to establish a national program to modify the course of the disease.

Call to Action: Those physicians at any institution who are treating hospitalized patients with COVID-19 can register their patients at the following website: Patients who have recovered from COVID-19 and are seeking to donate plasma should contact the national resource sharing network for a nearby blood donation center location. Groups such as Vitalant, America’s Blood Centers, and many others are working with physicians to collect and distribute donor plasma to hospitalized patients with severe or life-threatening COVID-19.