Doctors have been using plasma isolated from survivors of disease to treat other patients for over 100 years, with a high degree of safety and some degree of success. Thus far, though, we have had only small-scale studies to guide us in the usage of convalescent COVID-19 plasma to treat COVID-19 patients.
That has all changed with the publication by the Mayo Clinic of a large-scale study of over 5,000 patients with COVID-19 who were treated with convalescent plasma (much of which came from our incredible donors). Out of the 5,000 patients, only two had serious adverse events judged to have been from the plasma, demonstrating the low risk of the treatment.
While the Mayo Clinic study did not focus on how effective the treatment was, it is noteworthy that only 14.9% of the patients had died by 7 days after treatment. Since two-thirds of the patients who were treated were in intensive care units, which have mortality rates that range from 50% to 90%, it is exciting that this mortality rate is relatively low. Additionally, this study was performed on severely ill patients - doctors have anecdotally been seeing even more success with patients who are treated earlier. Read more here and here.