In Reply — Limitations of Safety Update on Convalescent Plasma Transfusion in COVID-19 Patients

This letter to the editors of Mayo Clinic Proceedings continues an ongoing scholarly conversation around the article "Safety Update: COVID-19 Convalescent Plasma in 20,000 Hospitalized Patients." The authors recognize the points raised in the preceding letter as crucial future steps in establishing the clinical efficacy of COVID-19 convalescent plasma as a therapeutic agent.

Main points include:

  • The primary purpose of the "Safety Update" article was to provide descriptive data on key safety metrics after transfusion of COVID-19 convalescent plasma in a specific cohort of critically ill patients.
  • Exploratory analyses of efficacy were beyond the scope of the article but are justified and forthcoming.
  • The U.S. COVID Plasma Expanded Access Program (EAP) was a pragmatic study design, organized to allow routine clinical care to dictate the timing and administration of plasma with the collection of real-world data. Further discussion is merited regarding the evolution of the EAP, including the logistic issues associated with conducting a randomized controlled trial on convalescent plasma — rather than or in addition to a pragmatic study design — during the COVID-19 pandemic.