To help COVID-19 patients, people across the country who’ve recovered from the virus are donating their plasma, the liquid part of blood composed mostly of water and proteins. Their plasma also contains COVID-19 antibodies, which helped them fight off the virus. The theory is that antibodies from recovered COVID patients can be used to help current COVID patients beat the virus too.
Plasma therapy has been used for more than 100 years to treat infections from viruses, including measles and mumps, the 2013 West African Ebola epidemic and the 2009–2010 H1N1 flu pandemic. In March of this year, the FDA approved “emergency use” of COVID-19 convalescent plasma as an investigational therapy for critically ill COVID-19 patients. (Plasma is called convalescent when it comes from a patient who’s recovered from a disease.)
Now clinical trials are underway around the world to see if plasma therapy can really help. Early research suggests it might. In a small study out of China, four out of five critically ill COVID patients who had plasma transfusions hit normal body temperatures within three days of beginning treatment, while three of the five patients were weaned off ventilators within two weeks. It’s hard to know exactly what these findings say about the efficacy of plasma therapy for COVID, though, because the study was uncontrolled (i.e., all patients enrolled in it received the experimental treatment). COVID-19 is also a new virus, and we’re still in the process of learning about how long it takes for symptoms resolve with and without treatment.
Researchers and doctors are waiting for results from larger controlled studies being run out of hospitals and medical centers. These facilities are relying on patients who’ve recovered from COVID-19 to sign up to donate plasma through a clinical trial. The Mayo Clinic is leading one of the biggest efforts, where patients can donate at one of more than 2,000 sites across the country.
You can also donate plasma through the American Red Cross. In this case, you won’t directly be a part of a clinical trial, though you could indirectly contribute to research if your plasma ends up going to a critical COVID patient who’s enrolled in a study.
Donating plasma is very similar to donating blood. “It’s painless and it’s a great way to help others,” says Jessica Donington, chief of thoracic surgery at University of Chicago Medicine and coordinator of the university’s COVID plasma clinical trial.
Here’s what you need to know before you donate plasma for COVID-19 purposes.
Who can donate?
Plasma donors need to have already had and recovered from COVID-19. People who are still recovering from the illness aren’t eligible. People who were never tested for COVID-19 but have tested positive for COVID antibodies are also now eligible, per the FDA. Female donors are eligible if they haven’t been pregnant, or if they’ve been tested since their most recent pregnancy and they’re negative for HLA antibodies. These antibodies, commonly found in pregnant women, aren’t harmful to women who have them, but in donated plasma, they can be dangerous to transfusion recipients.
Patients must have documentation of a positive COVID-19 nasal swab or a positive antibody test and be symptom-free. Some hospitals and trials ask donors to be symptom-free for 14 days, while others require 28.
Most centers are moving to 28 days, says Evan Bloch, an associate professor of immunology at the Johns Hopkins School of Medicine who’s facilitating a series of clinical trials at the school. That’s because many potential donors were continuing to test positive at around day 14, even though they had no symptoms.
Donors who’ve been symptom-free for less than 14 days need to have a subsequent negative COVID-19 test (following an initial positive test), which in most cases can be done at the donation site a few days before donating. The American Red Cross says their plasma donors need to be at least 17 years old, weigh at least 100 pounds and be in overall good health.
Is there a screening process?
Before getting the green light to donate, prospective donors typically need to fill out an online questionnaire and then go through a phone screening. You’ll be asked about your medical history (current medications, allergies), your coronavirus symptoms (when they started, how and when they resolved) and how you’re feeling now.
If you qualify, you’ll go to a hospital, medical center or Red Cross donation center to fill out more paperwork. These questions will address your travel history and delve further into your medical history.
In Houston, flight attendant Ashley Gillespie was referred to Methodist Hospital’s plasma donation program by her primary care doctor after recovering from a mild case of COVID-19. She emailed researchers a copy of her positive COVID-19 test. Then, for her pre-donation appointment, Gillespie arrived at Methodist, where a masked medical worker met her in the parking lot and took her temperature. Gillespie wore a mask as well.
Inside in a private room in the hospital, Gillespie had a physical exam that included blood pressure and heart rate readings. A technician took several vials of blood to test for COVID antibodies and other diseases that might disqualify her from donating. Clinical trial participants need to have high levels of antibodies, says Bloch. Gillespie also got a nasal swab test to make sure she no longer had COVID.
Later that day, Gillespie was cleared for donation, and she scheduled an appointment.
What happens the day you donate?
You’ll fill out more paperwork, sign a consent form, have your temperature taken, get weighed and likely have a fingerstick test to check your hemoglobin, which tells technicians if your blood count and iron levels are high enough to donate.
A phlebotomist in protective gear then inserts a needle in your arm, just like during a blood donation. The technician hooks the tube to a special machine that separates plasma from red blood cells. The machine collects one unit of plasma, and then returns red blood cells to the donor.
Also in Houston, Richard Garivey, an account manager for a local beer distributorship, has donated plasma to help COVID patients seven times at Houston Methodist. “The machine sounds like it’s spinning a million miles an hour, and I was scared it was going to take a toll on my body,” he says. “But the most strenuous part is squeezing a stress ball every 30 seconds to a minute. There’s nothing to it. It’s as easy as giving blood.”
At other facilities, like the University of Chicago, donors give whole blood versus just plasma to help with current blood bank shortages. Donors who give through the university’s treatment trial give blood on site at the university’s blood donation center. “We give our blood bank the red blood cells, and we take the plasma,” Donington says. White blood cells go to a research lab at the university for vaccine-related research.
“We do it all under one roof,” says Donington. “That’s what’s unique about our program.”
How long does donating take? What does it feel like?
Garivey says the donation process takes him around 30 minutes, and the phlebotomist stays by his side the entire time. During donations, he’s made comfortable with pillows and blankets, and snacks and drinks are available. He plans to continue donating twice a week as long as he can.
“It’s a good thing,” he says. “If you have it in your heart to help somebody, you should.”
Gillespie felt weak after donating, but she pepped up just a few hours later. “It doesn’t hurt,” she says. “It was easy-peasy. And it’s a really positive place to be at a time like this. You feel good about what you’re doing.”
She suggests staying well hydrated before and after donating. Gillespie was surprised to receive $100 each time she donated, which she’s passing on to her local food bank. (Compensation is typical for clinical trials; the Red Cross doesn’t pay donors.)
Are there any health risks to know about?
Donating plasma comes with the same risks as donating blood, such as bruising, hematomas (when blood leaks from large vessels), nerve damage, discomfort at the needle site, vomiting and fainting. The most serious of these risks are very rare.
Bloch also says many patients wonder if donating plasma, and especially multiple times, can affect their own long-term immunity — i.e., could their antibody levels drop, leaving them less resilient to the virus if they’re re-exposed to it?
“I would say not,” he says. “Independent of COVID-19, you have people that give frequent plasma donations, coming in weekly, and they have no real adverse effects. Your body will regenerate antibodies.”
How will doctors use your plasma?
For now, most plasma is being given to critically ill COVID patients, including those who are on ventilators. Because of privacy rules, researchers and doctors aren’t allowed to give donors details about who receives their plasma or how they fare.
Researchers told Garivey that every time he donates, he can potentially help two COVID patients. “I ask if it’s helping [patients],” he says, “and they can’t disclose that information because of HIPAA rules. But they’re smiling when I ask them.”
What’s the best way to donate or find a clinical trial?
The American Red Cross website is a good place to start. If you live in a major metropolitan area, you can also check if your local hospital or medical center is running a program or clinical trial. You can search current clinical trials online at ClinicalTrials.gov
What’s next for plasma therapy?
If plasma therapy proves effective, it could possibly be expanded to include COVID patients who aren’t critically ill. At Johns Hopkins, Bloch is helping coordinate several other clinical trials to test plasma with noncritical patients. He hopes they’ll be underway soon.
Trials in the works include one that looks at how plasma could help recently infected patients without severe symptoms. Another will study whether plasma could prevent COVID-19 in high-risk populations like healthcare workers and those with pre-existing conditions.
“The clinical trials are enormously important,” Bloch says. “They’ll inform practice so the right patients actually get the stuff. If you donate, it’s really helping.”