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Plasma is taken from people who have recovered from the disease and given to people still battling COVID-19. Getty Images
  • The FDA has approved using convalescent plasma to treat COVID-19.
  • Experts are wary that the data cited in approving the treatment was taken out of context from the study.
  • The treatment involves taking plasma from people who have recovered from the disease and giving it to people with COVID-19 to help their immune system fight the illness.

All data and statistics are based on publicly available data at the time of publication. Some information may be out of date.

On Aug. 23, the Food and Drug Administration (FDA) issued an emergency use authorization (EUA) for convalescent plasma therapy to treat COVID-19.

Convalescent plasma (CP) therapy involves transfusing blood plasma (the liquid part of blood) from patients that have recovered from the disease to treat people who currently have COVID-19.

“Convalescent plasma contains antibodies, which are specialized proteins that fight infections in the body. Antibodies are contained in the plasma, the liquid component of blood that suspend different types of blood cells,” Dr. Robert Glatter, an emergency physician at Lenox Hill Hospital, New York, told Healthline.

Glatter explained that the plasma is harvested, tested for safety, and then purified in order to separate the antibodies. It can then be infused into a patient ill with COVID-19.

Glatter said convalescent plasma carries minimal risk of “allergic-type reactions, transfusion-associated circulatory overload (TACO), or transfusion-related acute lung injury (TRALI),” which can occur with any plasma or blood transfusion. He emphasized that CP is also screened for SARS-CoV-2, HIV, and hepatitis types B and C.

According to the FDA, initial treatment involves injecting a little less than 8 ounces of plasma over a 1- to 2-hour period. However, additional infusions of plasma “may occur throughout your hospital stay if the treating physician determines that additional treatments are clinically justified.”

“The data from studies conducted this year shows that plasma from patients who’ve recovered from COVID-19 has the potential to help treat those who are suffering from the effects of getting this terrible virus,” FDA Commissioner Dr. Stephen M. Hahn, said in a statement.

This month, a panel convened by the National Institutes of Health (NIH) found that there is not enough evidence showing that the treatment is safe and effective.

In a statement released by the NIH, the panel found there’s no data that the treatment makes any difference in the 7-day survival for patients with COVID-19.

“There are currently no data from well-controlled, adequately powered randomized clinical trials that demonstrate the efficacy and safety of convalescent plasma for the treatment of COVID-19,” the panel said in a statement.

Dr. Thomas M. File Jr., FIDSA, president, Infectious Diseases Society of America (IDSA), said that while the current data shows some positive signals that convalescent plasma can be helpful in treating patients with COVID-19, especially if given early in the disease, there isn’t enough evidence yet to prove it’s beneficial.

“We lack the randomized controlled trial data we need to better understand its utility in COVID-19 treatment,” said File in a statement. “For this reason, IDSA supports the continued collection of data in randomized clinical trials to better understand the benefits of convalescent plasma treatment before authorizing its wider use in patients with COVID-19.

Dr. Teresa Murray Amato, chair, emergency medicine, Long Island Jewish Forest Hills, in New York City, agrees.

“Although the gold standard of a randomized controlled study was not done, the data suggest a positive correlation of plasma use and survivability from COVID. There did not appear to be any increased harm,” she said.

The EUA is based on a trial from the Mayo Clinic, which has not yet been peer-reviewed. The findings suggest that convalescent plasma could be effective against COVID-19.

The study involved 35,000 hospitalized patients with COVID-19 who were treated with CP. The results suggested lower 7- and 30-day mortality rates, especially with plasma containing higher antibody levels. It also did not involve a placebo group. Instead, people were given higher or lower doses of plasma at different points after their diagnosis.

Researchers saw a reduction in mortality in patients that were treated within 3 days of diagnosis, compared with those who were treated 4 or more days after. People who had higher doses of plasma also had better survival rates.

During a press conference, Hahn initially said that the data showed that 35 out of 100 people with COVID-19 could be “saved” due to this treatment.

However, this information was based on a very small subgroup of the study: people who were not on ventilators who received plasma within 3 days of diagnosis. And it was not accurate. The data actually showed that people who had a low dose of plasma had about a 13 percent risk of dying, compared with an 8 percent risk among people who had high doses of plasma.

The 35 percent refers to the percent change from 13 to 8 percent.

He later apologized for the misleading statements on the data.

“For the first time ever, I feel like official people in communications and people at the FDA grossly misrepresented data about a therapy,” Dr. Walid Gellad, who leads the Center for Pharmaceutical Policy and Prescribing at the University of Pittsburgh, told the New York Times.

Amato maintained that during the current pandemic, it’s important to look at all options.

“Since COVID-19 is a novel strain of a coronavirus not before seen in humans, it may not be possible to fully investigate treatment options during this outbreak,” she said. “Treating physicians have to weigh the possible harm and possible positive effect before making decisions. But again, whatever treatment we give, we want to be reasonably assured that we are not actually harming patients.”

Amato continued, “Physicians are trying to quickly expand treatment options for patients that become critically ill from COVID.” She added that if a treatment appears to be safe and may offer a better outcome, there’s “a tendency to use that pending a more rigorous study.”

According to Amato, the FDA has looked at many treatment options, and “some do appear to be safe and possibly effective for the treatment of COVID 19.”

She said antiviral medications are being studied, and a steroid drug called dexamethasone has been shown to be safe and possibly effective for patients who are critically ill with COVID-19. “Other steroids may be effective as well but have not yet been studied. Some anti-inflammatory medications are being looked at, but there is no clear data as of yet.”

However, previous EUAs have been reversed when better information became available.

“Although anti-malaria medications hydroxychloroquine and chloroquine were originally thought to be possibly effective treatments for COVID, they were shown to be ineffective and possibly harmful due to cardiac side effects, and their authorized use for COVID was withdrawn by the FDA,” said Amato.

“Researchers began to look at convalescent plasma early during the pandemic, simply because there were no significant therapeutic options available,” said Glatter.

But while the Mayo Clinic program offered expanded access to CP for COVID-19, the lack of a placebo group raises questions.

“So it’s unclear how useful the plasma treatment may ultimately be,” said Glatter. “The bottom line is that we need more randomized placebo-controlled trials to study the efficacy of convalescent plasma.”

The FDA has issued a EUA for convalescent plasma therapy, a method that uses the blood of people who have recovered from COVID-19 to treat patients recently diagnosed with the illness.

The decision was based on research by the Mayo Clinic, which didn’t use a placebo group. Experts say that this makes it difficult to judge how effective treatment might be.

They also say that if a treatment appears to be safe, there’s a tendency to use it while waiting for more rigorous research.

EUAs have been revoked in the past when more information became available — the anti-malaria drug hydroxychloroquine being one example.