Plasma Transfusion Therapy – FDA Allows the Use of Blood from Recovered COVID-19 Patients for Critically Ill Patients

The US Food and Drug Administration (FDA) has updated its rules on the use of experimental treatments for the ongoing COVID-19 outbreak. Accordingly, when a patient's life is seriously or immediately threatened by COVID-19, the disease caused by the novel coronavirus, ‘plasma from a recovered patient’ may be used only in critically ill patients on an experimental basis. However, this use is conditional on a case-by-case approach in special circumstances: ‘permission’ has been granted, while its use as a treatment for COVID-19 has not yet been approved, as was emphasized. Although the FDA has permitted its use in limited circumstances, it believes that plasma from recovered patients could contribute to research into highly effective treatment.

Although clinical trials on this subject have not yet been completed, the FDA granted this temporary permission in response to the current public health threat and as part of the fight against COVID-19. Meanwhile, preclinical and clinical studies on the use of plasma from recovered patients are continuing. Existing studies provide some promising signs that recovered-patient plasma may indeed be effective against the novel coronavirus (SARS-CoV-2).

Plasma is the liquid part of human blood apart from red blood cells and is obtained by separating it from red blood cells using a special method. Plasma helps the body's immune system respond through its especially important antibodies, and is a blood component of great importance to our health. Plasma is used by direct transfusion / blood transfusion into a patient (giving blood or blood products to another person intravenously).

People who become ill because of a virus and then recover typically develop immunity to that virus. The duration of immunity may vary. It may be long-lasting, as in chickenpox, or short-lived, as in flu (influenza). In theory, it should be possible to take antibodies from someone who has already developed them and transfer them to a patient whose immune system is not doing a good enough job of producing its own.

Plasma transfusions from recovered patients have been used in some cases during previous outbreaks, including those of H1N1 flu, SARS and MERS.

Results from a study on the use of plasma against COVID-19 have been shared. Recently, plasma from people who had recovered from COVID-19 was transferred to 10 patients with severe COVID-19 infection. In this study, antibody levels were observed to ‘rise rapidly’ immediately after transfusion in five of the 10 cases (the other four patients already had high antibody levels, which remained high). Within a week, the virus was no longer detected in seven patients.

Although these findings are not considered a formal clinical trial, other small-scale investigations in clinical practice have shown similar results.

New York Governor Andrew Cuomo announced that state health institutions would begin a trial of plasma from recovered patients this week. FDA Director Dr. Stephen said at a White House coronavirus briefing last week that the results were promising for this early stage.

Early results from some studies have shown that plasma transfusions may be effective when used for prophylaxis (prophylaxis: a preventive medical intervention given to healthy people before they develop a disease). However, the FDA does not yet recommend such use in practice.

As mentioned, plasma therapy from recovered patients is not new. It also has the advantage of being relatively safe compared with other treatments. However, it must be confirmed that the plasma donor is no longer carrying active virus.

In Türkiye, it has also been announced that COVID-19-specific plasma transfusion therapy for prevention and treatment will begin in April as part of a clinical trial.

As with any proposed treatment, a great deal of testing and research is needed before this therapy can be approved and recommended for general use. Many studies are still underway to find an effective treatment during this outbreak. Although definitive results from such studies have not yet been established, they are important because they offer hope to patients.