Most patients beat COVID-19 without serious complications because their immune systems create antibodies that prevent the virus from infecting their cells.
What if you could transfer some of the antibodies from those who’ve recovered to the most at-risk people, such as the elderly and people with existing health conditions, to assist them in their battle?
That is precisely what scientists at university hospitals and other research centers around the world are scrambling to do.
Known as “convalescent plasma” therapy (CPT), the experimental treatment for COVID-19 is actually an old tool that has actually been used in various forms for well over a century.
Unlike vaccines, which train the body to create its own permanent antibodies, CPT merely offers temporary protection, but still it may mean the difference between life and death for the most at-risk patients.
And scientists are excited about CPT for several reasons. The treatment has been used with varying degrees of success against past epidemics, including SARS, which is similar to COVID-19. Additionally, two preliminary studies shared by Chinese doctors showed promising results. The FDA has opened the doors for limited trials in the United States, and the first patients are already receiving this treatment.
If things go well with the testing, CPT could, in principle, be made available on a mainstream basis fairly quickly and help turn the tide on the battle against COVID-19.
This is a rapidly evolving story with scientists working around the clock at university hospitals and research labs with some international coordination. We will update this article to reflect the latest information about its progression as we learn about it.
How CPT works
Blood from convalescent or recovered patients is collected and then separated or fractionated into the component parts — red blood cells, white blood cells, platelets and plasma. This is generally carried out by blood centers, which fractionate the blood using centrifuges and other equipment.
The plasma, which contains the antibodies, is first analyzed to determine its strength and treated to deactivate infectious agents.
Then the plasma is administered to patients who need it, providing them with the borrowed antibodies.
In mid-March, researchers at Mount Sinai’s Icahn School of Medicine, in collaboration with scientists in Australia and Finland, were among the first to develop an antibody test that detects the COVID-19 antibodies in a person’s blood. They shared their test with other laboratories around the world so they can replicate it during the pandemic.
To make the process more scalable, private companies like California-based Biomerica Inc. and South Korean test maker Sugentech, Inc. have created and are already selling pin-prick tests for COVID-19 antibodies outside the United States. One company, Chembio Diagnostics Inc. of Medford, New York, has already received a $4 million order from Brazil and has plans for its antibody test at several U.S. sites.
How CPT has been used in the past
A type of CPT was first used on patients with diphtheria over a century ago. In 1901, Emil von Behring won the first Nobel Prize in Physiology and Medicine for his diphtheria treatment, which involved injecting the antibodies taken from animals who had recovered from diphtheria to people suffering from the disease.
Since then, CPT has been used to fight several outbreaks.
It was shown to cut the fatality rate of the 1918 flu pandemic in half for patients who received the antibodies from those who had already recovered. In the 1930s, CPT was found effective for the treatment of measles. More recently, this method has been tested in outbreaks of other respiratory infections like the 2009-2010 H1N1 influenza virus pandemic, the H5N1 influenza, the 2012 MERS-CoV epidemic and Ebola, with varying degrees of success.
CPT also showed great promise during the 2003 SARS-CoV-1 epidemic. This is significant in that COVID-19 is similar to SARS.
The largest study involved 80 patients with SARS in Hong Kong, who were treated before day 14 and showed improved prognosis over people who were not administered the treatment.
There is also some anecdotal information on the effect of CPT on three patients seriously ill with SARS in Taiwan, who all survived after treatment.
Current battle to thwart COVID-19 using CPT
- February 27, 2020 — WSJ op-ed ignites a scientific grassroots effort
CPT recently burst into mainstream news in February when Arturo Casadevall, chair of molecular microbiology and immunology at the Johns Hopkins Bloomberg School of Public Health, penned a Feb. 27 op-ed in the Wall Street Journal, advocating the treatment as a stop-gap approach to “protect the vulnerable with the antibodies in the blood of those fortunate enough to have recovered.”
Since then, university hospitals and medical centers around the world are coordinating their efforts to make the treatment a reality. Some of them, in fact, were already testing the procedure on patients severely ill with COVID-19.
The largest collaboration to date is the National COVID-19 Convalescent Plasma Project, a group of physicians and scientists from 34 U.S. institutions, who have self-organized for the purpose of investigating the use of CPT to battle COVID-19 and are led by a renowned leadership group consisting of:
- Arturo Casadevall, M.D., Ph.D. (Chair), Johns Hopkins University
- Benjamin Chen, M.D., Mount Sinai School of Medicine
- Michael J Joyner, M.D., Mayo Clinic School of Medicine
- Jeffrey P Henderson, M.D., Ph.D., Washington University School of Medicine
- Nigel Paneth M.D., MPH, Michigan State University
- Liise-anne Pirofski, M.D., Ph.D., Albert Einstein College of Medicine
- Shmuel Shoham, M.D., Johns Hopkins University
In addition to U.S. efforts, similar attempts to test CPT are underway in Iran, Israel and the UK. Clinical trials are also underway at Mazandaran University of Medical Sciences in Iran and the Shanghai Public Health Clinical Center in China, as well as the Mayo Clinic and Johns Hopkins in the United States.
The pace at which COVID-19 is spreading has created the need for scientists to work around the clock to evaluate CPT’s efficacy.
- March 16, 2020 — Researchers from Wuhan, China, issue a preprint report that showed some promise
News from China suggests that CPT is worth pursuing as a stop-gap measure.
On March 16, in a preliminary preprint report (the “Wuhan Report”), researchers from Beijing, Wuhan and Shanghai shared that the symptoms of 10 patients who were administered CPT improved significantly after three days. And seven of the 10 patients had undetectable levels of the virus within six days.
While the Wuhan Report involved cases that were limited and not conducted as a proper scientific study, two pathologists at Emory University School of Medicine — John D. Roback and Jeannette Guarner — noted that the results were promising in an editorial they penned on March 27:
“The intervention, administration of convalescent plasma, was not evaluated in a randomized clinical trial, and the outcomes in the treatment group were not compared with outcomes in a control group of patients who did not receive the intervention. Therefore, it is not possible to determine the true clinical effect of this intervention or whether patients might have recovered without this therapy. In addition, patients received numerous other therapies (including antiviral agents and steroids), making it impossible to disentangle the specific contribution of convalescent plasma to the clinical course or outcomes. Moreover, convalescent plasma was administered up to 3 weeks after hospital admission, and it is unclear whether this timing is optimal or if earlier administration might have been associated with different clinical outcomes. Despite these limitations, the study does provide some evidence to support the possibility of evaluating this well-known therapy in more rigorous investigations involving patients with COVID-19 and severe illness.” (emphasis added)
- March 24-26, 2020 —The FDA opens the door for testing the treatment
In acknowledgment of the “public health emergency that the expanding COVID-19 outbreak presents,” the FDA issued an Investigational Order on March 24, allowing licensed physicians to try CPT in patients “with serious or immediately life-threatening COVID-19 infections.”
The FDA is permitting the emergency investigational use of CPT because there are no approved treatments. However, licensed physicians must still get pre-authorization from the FDA for each patient to be treated with CPT, which is currently limited to people seriously ill with COVID-19 and not responsive to other treatment.
On March 26, the FDA issued FAQs to help health care providers and potential blood donors.
- March 25, 2020 — Plasma collection begins
Many hospitals throughout the United States are preparing to accept blood donations and administer CPT in patients ill enough to warrant the treatment.
Since March 25, the New York Blood Center has been working in direct coordination with Mount Sinai Hospital, which is identifying viable candidates who have fully recovered from COVID-19 and sending them to NYBC to donate their blood.
- March 27, 2020 — More promising Chinese data are shared
On March 27, researchers from Shenzhen Third People’s Hospital in China shared a report, detailing their use of CPT in five patients critically ill with COVID-19. Within days, their conditions improved — their fevers subsided and other symptoms improved. Within two weeks, their viral load declined. Four of the patients no longer needed mechanical ventilation after nine days. Three of the patients were discharged from the hospital and the other two were deemed stable a little over one month after the treatment began.
“If the results of rigorously conducted investigations, such as a large-scale randomized clinical trial, demonstrate efficacy, use of this therapy also could help change the course of this pandemic,” Roback and Guarner wrote in their March 27 editorial.
- March 28, 2020 — First U.S. patient receives CPT
On Saturday, March 28, the FDA approved the first COVID-19 patient for CPT at Houston Methodist Hospital.
“What we did is transfused COVID-19 convalescent plasma to two critically ill patients,” Dr. Eric Salazar, the principal investigator and a physician-scientist at Houston Methodist, said in a news release.
Houston Methodist physicians started recruiting blood plasma donors on March 27 from approximately 250 patients who had tested positive for the COVID-19 virus at the hospital.
How to donate your plasma
A handful of blood centers and the American Red Cross are gearing up to take plasma donations.
If you have recovered from COVID-19 and wish to donate plasma, you should contact one of these organizations below:
- Mount Sinai Convalescent Plasma Donation
- Columbia University Convalescent Plasma Donation
- National COVID-19 Convalescent Plasma Project
- Red Cross
Four NBA players who have beaten COVID-19, including Marcus Smart of the Boston Celtics, reportedly intend to donate their blood. Their participation will help shine a light on this important cause.
For now, only people who tested positive for COVID-19, have fully recovered and are system-free can donate their plasma.
However, given that there are likely many more untested people who have had COVID-19 and recovered from it, there may be a movement to allow donations from them based on an antibody test, as those tests get FDA approval and become more widely available.
Peter Corrigan is the CEO of The University Network. TUN is a student news and resource platform that advocates for students.