Convalescent plasma (CP) is not a new therapy, but it’s gotten new attention. For illness that has progressed to respiratory distress, physicians in hospitals have prescribed convalescent plasma for COVID-19 patients, along with other treatments like steroids and antiviral medications that are generally well established for this clinical scenario from similar infectious agents. Because of both theoretical benefit and observational success, studies have begun to emerge about the application of convalescent plasma for COVID-19 specifically. With early encouraging results suggesting improved survival rates for tens of thousands of individuals, the White House administration urged the United States (U.S.) Food and Drug Administration (FDA) to establish emergency use authorization (EUA). Despite the preliminary success, this move remains controversial because the usual degree of research scrutiny has not been applied to convalescent plasma for COVID-19. Studies are ongoing.
Proponents say convalescent plasma has been around for a long time for similar purposes, what could be the harm? (Well – think hydroxychloroquine…) Skeptics say the move is premature. The middle ground would have been to continue in the previous capacity of FDA investigational (also called compassionate) use. That allows doctors to make informed clinical decisions to use CP when the patients’ circumstances warrant, with documentation and agreement that the patient is aware of the experimental nature of the therapy, and with meticulous tracking of many details that would become clinically relevant and inform well-substantiated application of the treatment as we move forward.
Now, some experts worry that the EUA might jeopardize research. Having the medication readily available for this purpose may translate to fewer people enrolling in studies since doctors can obtain the drug for patients without requesting the added demands of participating in a clinical trial. Given the positive publicity about convalescent plasma, patients may not take the chance of being assigned to a placebo group and, thus, not receive the therapy. The EUA may also lead to diminished tracking which helps delineate important details regarding the treatment, like dosing and timing of administration as well as potential risks, side effects, and negative reactions.
The idea of convalescent plasma is to gather blood from patients who have recovered from the infection and, thus, developed antibodies that might confer immunity to someone who currently has the illness. In theory, the antibody-rich blood product should help patients recover faster from COVID-19. Since there is no confirmed effective treatment for COVID-19, the idea of boosting patients’ immune response to the virus seems worthwhile.
The therapy has been around since early in the 20th century and has been used successfully for other viruses, including hepatitis, mumps, measles, rabies, polio, and the 1918 influenza pandemic. More recently, it’s even been used for H1N1 flu, Ebola, and previous coronavirus outbreaks like Severe Acute Respiratory Syndrome -1 (SARS-1) and Middle Eastern Respiratory Syndrome (MERS). However, it remains unclear whether convalescent plasma adds benefit to standard treatment. The way to determine this involves studies using a rigorous design known as randomized controlled clinical trials (RCTs) for hospitalized patients with COVID-19.
Without such scientific analysis, many questions remain unresolved about the proper way to administer the therapy
Without such scientific analysis, many questions remain unresolved about the proper way to administer the therapy – including exactly who will benefit, at what stage of the COVID-19 infection, and what dose confers protection.
Data from Chinese researchers suggests benefits like xray resolution of lung infections from COVID-19, a reduced viral load, and improved survival. However, the data is extremely limited, including that that study was discontinued due to low rates of enrollment and lack of added clinical benefit from convalescent plasma. There are several assessments going on currently in the U.S., including through the University of North Carolina (UNC) and an expanded (again, called compassionate) use program led by the Mayo Clinic in Minnesota. The latter is from where much of the information about CP use in COVID-19 patients has been derived to date.
In the meantime, under what appears to be possible pressure from the White House Administration, and against the advice of some prominent experts, the FDA issued the EUA on August 23rd, 2020 for convalescent plasma.
Given the change in FDA status, there has been a surging interest from hospitals continuing to struggle with high numbers of people with COVID-19. This has translated to accelerated demand for convalescent plasma. Blood banks around the country are shipping CP to states like Florida, Texas, Tennessee, Mississippi, Missouri, and California. Organizations leading these efforts include the Red Cross and America’s Blood Centers.
If you’ve recovered from coronavirus and test positive for COVID-19 antibodies, you might be eligible to donate convalescent plasma; the FDA explains.
If you’ve recovered from coronavirus and test positive for COVID-19 antibodies, you might be eligible to donate convalescent plasma; the FDA explains. Even one donor can benefit three to four patients with matching blood types.
Written By Rohan Prabhu & Jacki Hart, MD