Convalescent plasma therapy has given doctors hope that an effective treatment for the coronavirus is already here, even if the evidence of its successes is anecdotal.
“Whether it is effective as a treatment, I can give you anecdotal experience,” said Dr. Sohail Rao, executive vice president of the DHR Health system in Texas. “It is a very safe procedure, and it is also very effective because we have seen patients who we were able to get them off the ventilator fairly quickly.”
Convalescent plasma therapy is an experimental treatment in which doctors take blood from a patient who has recovered from COVID-19 and whose body has antibodies that it created to fight the virus. Doctors then take the liquid part of the blood, called plasma, and transfuse it into the patient’s blood.
The therapy is not new. Physicians have been using convalescent plasma transfusion to treat infectious diseases for more than 100 years. It has not yet been clinically proven to treat the coronavirus, but the therapy has proven to be safe.
A June report published in the medical journal JAMA showed that side effects of receiving a plasma transfusion are minimal and the most common is a mild allergic reaction. Research shows that it might be most effective when given to patients early in the course of the disease.
A limited study published in May in the American Journal of Pathology found that 9 out of 25 COVID-19 patients showed improvement after seven days of receiving the therapy and 7 of the 9 patients were discharged from the hospital. By day 14 after receiving plasma transfusions, 19 patients’ conditions had improved, and an additional four were discharged.
Members of the Trump administration have touted the promise of plasma transfusion as well. Food and Drug Administration Commissioner Stephen Hahn said in a House health committee hearing in June that the therapy’s efficacy is “quite encouraging” but did not offer a timeline for which the FDA may approve the therapy to treat COVID-19.
“There is not enough evidence to actually make a confirmatory statement that these antibodies actually afford protection and that they will protect you in the future,” Rao said. “But the very fact that they develop antibodies gives you some confidence that the immune system is using the antibody pathway to get rid of the virus.”
While some intensive care doctors say the therapy has been shown to shorten recovery time and hospital stays, they point out that the treatment is not easily accessible.
“Accessibility is a big issue,” said Dr. Jaya Prakash Buddineni, an internist at Florida Hospital Tampa. “So far, at Tampa hospital, I think there’s a seven-day lag. So I have to put in for the therapy today, and it’s literally taking me between five to seven days for them to get the therapy.”
The benefits of the therapy are becoming more apparent, and doctors use it and have increased optimism that a treatment for COVID-19 may not be too far off. However, plasma with coronavirus antibodies is not easy for doctors to get.
Part of the issue, Buddineni said, is that few recovered patients donate blood for other COVID-19 patients: “I mean, how many patients are really donating plasma? And how many are being tracked by the state authorities? I don’t think they’re doing that.”
He added that some doctors he works with have said that convalescent plasma therapy may work better than remdesivir, another possible treatment for the coronavirus currently used in many hospitals, in speeding up recovery, but it’s too soon to make that conclusion.
There are still many unknowns about the efficacy of convalescent plasma therapy, including whether antibodies actually provide COVID-19 patients protection from more coronavirus infection. Buddineni said there are more unknowns than knowns about antibody treatment and that it could take another six months of clinical research to get answers.
