Note: This article was last updated in September 2020. For the latest updates on COVID-19, see Piedmont.org.
Convalescent plasma therapy uses blood from people who've recovered from an illness to help others recover. Because there is currently no approved treatment for COVID-19, last month, the Food and Drug Administration (FDA) authorized convalescent plasma as an emergency-use treatment during the pandemic.
“It’s an experimental therapy for COVID-19,” says Amy Hajari Case, M.D., Piedmont pulmonologist and medical director of Pulmonary and Critical Care Research. “The theory is that, in people who have recovered from COVID-19, their body’s immune system has learned to recognize the virus. They have developed antibodies, or proteins, in their blood that have helped their body attack the virus.”
These antibodies can be harvested through plasma donation. Once the plasma is collected, it is then given to hospitalized COVID-19 patients who haven’t developed an immune response to the virus on their own.
“It takes time for any body’s immune system to learn to recognize the virus and generate antibodies,” she explains. “So, giving a COVID-19 survivor’s passive immunity to another person who is fighting the virus may enhance that person’s ability to fight the virus.”
She notes that there is currently a national shortage of plasma because it is being used broadly across the United States. There is still a significant need for plasma donations from people who have recovered from COVID-19.
“Plasma is a resource that comes only from the altruism of people who have recovered from COVID-19,” says Dr. Case. “It cannot be made or manufactured; it must be donated.”
How effective is convalescent plasma for treating COVID-19?
“The jury is still out on how effective it is,” says Dr. Case. “From a scientific standpoint, it sounds like a good idea, but it still needs to be proven in clinical trials. In the past, the idea of passive immunity from convalescent plasma was shown to be beneficial, but other times it didn’t work as well. Whether it works for COVID-19 remains to be seen.”
Is convalescent plasma safe?
She notes that the Mayo Clinic has collected a large body of evidence that shows convalescent plasma is generally safe, though there are some risks associated with the therapy.
“When doctors take care of patients, they decide who will benefit from convalescent plasma on an individual basis,” she says. “They try to weigh the risk and benefits.”
Who is a candidate for convalescent plasma?
Dr. Case says currently only hospitalized patients are candidates for convalescent plasma therapy.
“These patients must be ill enough to be hospitalized with respiratory issues from COVID-19,” she says.
She also notes that based on the current research, the timing of the treatment could be important.
“We think it is not likely to be effective in late-stage disease,” she says.
The need for plasma donation
“Doctors in hospitals across the country are using convalescent plasma in conjunction with some more proven therapies,” she says. “The trouble is, the demand has outstripped the supply. So many people are getting hospitalized that the supply has not been able to keep up.”
The early evidence suggests that patients did not benefit when they received convalescent plasma later after their diagnosis. Dr. Case says the national shortage may limit how quickly patients are able to receive the treatment and, possibly, the plasma’s effectiveness.
“We’re having a delay in the arrival of plasma unit orders from blood banks because they don’t have the supply,” she explains. “Depending on the patient’s blood type, a unit may not be available to them for a week or longer. At that point, we’re probably outside the window of when it could be beneficial.”
Convalescent plasma: How you can help
“The demand for plasma has increased so significantly that we’re asking people who are able – who have recovered from COVID-19 and are healthy and strong enough to go out and do so – to consider plasma donation,” says Dr. Case. “It has the potential to help multiple people and you can even donate more than once as long as your antibody production continues. Every donation could help with some of the supply limitations for this experimental therapy.”
The Red Cross makes it easy to donate plasma, she notes. “They have a self-referral form you can complete online and then someone from the Red Cross will contact you to set up a time to donate if you’re a candidate.”
According to the Red Cross, candidates must:
- Be at least 17 years old.
- Weigh at least 110 pounds.
- Be in good health.
- Have a prior and confirmed COVID-19 diagnosis, but are now without symptoms.
“Convalescent plasma is still an experimental treatment even though it holds promise, which is why we’re using it in certain patients in the hospital,” she says. “Plasma donation is something that people who have had COVID-19 can do to help others.”
COVID-19 prevention
Whether you’ve had COVID-19 or not, Dr. Case reiterates that there are still three important things you can do to help yourself and others during the pandemic:
“To slow down the spread of the virus, we can and should keep doing these things that are working,” she says.