Convalescent plasma therapy showing promise against COVID-19

As physicians grapple with the best ways to treat patients infected with the coronavirus, one treatment that has gained increasing attention is convalescent plasma therapy.

This therapy involves transfusing blood plasma from recovered coronavirus patients into a sick patient. The plasma contains a specific antibody that helps the immune system fight the virus. The idea is to help give seriously ill patients an immune-system boost so they can better fight off the virus.

COVID-19 convalescent plasma therapy is considered as an investigational product by the Food and Drug Administration. 

Dr. Jamie N. Nadler, the medical director of quality and patient safety for Buffalo General Medical Center and Gates Vascular Institute in upstate New York, recently told the Buffalo News that there’s some evidence that it could be an effective way to treat COVID-19. 

"There have been small trials and small attempts around the world that seem to have had some degree of success," Nadler said. "So it's worth trying as long as it's done correctly."

Nadler is right: We found two studies of convalescent plasma therapy that have shown  at least initial promise with COVID-19 patients, although experts caution that more investigation is needed. (Nadler did not respond to an inquiry for this article.)

Convalescent plasma therapy has a long history. It was developed by Paul Ehrlich and Emil von Behring for treatment of diphtheria, a finding that was recognized in 1901 with the first Nobel Prize for medicine, epidemiologist Dr. Ian Lipkin, a professor at Columbia University’s Mailman School of Public Health, told CNBC. 

More recently, it was used against Severe Acute Respiratory Syndrome, an infection with similarities to COVID-19 that emerged in Asia in the early 2000s. 

In one study in Hong Kong during a SARS outbreak, a hospital treated 80 patients with convalescent plasma. Among the treated patients, the study showed a higher discharge rate prior to day 14 of the illness: 58.3% became well enough to be discharged, compared with 15.6% of those who did not receive the treatment.

However, patients suffering from Ebola — a different kind of virus in the filovirus family — did not experience positive results from convalescent plasma treatment. 

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A Chinese study, published in the Journal of the American Medical Association, described a study treating five critically ill COVID-19 patients with convalescent plasma. All five patients, ranging from 36 to 65 years old, began the study while on ventilators. 

Following the transfusion, the authors reported, four of the five patients’ body temperatures normalized within three days. Other key metrics, including viral loads, improved within 12 days.

The hospital discharged three of the five patients. The remaining two were in stable condition 37 days after the transfusion. 

The authors concluded that this represented an "improvement," but cautioned that the limited sample size and study design precluded "a definitive statement about the potential effectiveness of this treatment."

Another Chinese study found similar results. It has not yet been peer reviewed but has been published online. 

In the study, 10 patients with severe cases received a dose of convalescent plasma. Within three days, the viral load became undetectable in seven patients, with no adverse effects. In addition, fever, cough, shortness of breath and chest pain disappeared or significantly improved in all 10 patients within one to three days of the transfusion.  

The authors concluded that the therapy was "well tolerated and could potentially improve the clinical outcomes" in severe COVID-19 cases. However, they added, questions on the optimal dose and timing need further investigation.

"Just as COVID-19 has taken us back to classic methods for outbreak containment like isolation, through a novel use we are rediscovering the lifesaving potential of a classic strategy like plasma therapy," Lipkin said. 

Experts say that convalescent plasma therapy is promising, but much more work is needed.

"There have not been any breakthroughs recently," said Jessica Donington, a professor of surgery at the University of Chicago and chief of the thoracic surgery section. But, she added, "it all has been going on very quickly," with larger clinical trials in the works.

Nadler said that "there have been small trials and small attempts around the world" to test convalescent plasma therapy for coronavirus patients, and they "seem to have had some degree of success."

We found two Chinese studies that have found initial success, though more research is needed to confirm these results more broadly. We rate the statement True.