The U.S Food and Drug Administration this week gave emergency approval for the expanded use of blood plasma to treat Covid-19, making the treatment more available to those who want it.
Convalescent plasma, as it’s known, comes from blood taken from people who are recovering from Covid-19. The blood is spun down to remove red and white blood cells, leaving a pale yellow liquid that contains antibodies. That serum can be injected into a patient early in an infection to help them fight the virus.
While the treatment is considered safe, scientists can’t say for sure whether it works because there haven’t been many clinical trials with control groups. Setting up those studies has been difficult, because sick people are generally unwilling to sign up for a trial in which they might get a placebo.
Among the limited studies that have been done, researchers found that the treatment showed the best results among patients under 80 years old and not on a ventilator, who received plasma with a high level of antibodies within three days of diagnosis.
President Trump had been pushing for expanded use of the treatment over the concerns of top government scientists who argued that the data was too weak. Our colleague Donald G. McNeil Jr. told The Daily that Mr. Trump’s approach might end up doing more harm than good.
“It’s exactly what happened with hydroxychloroquine,” he said. “It was talked up so much that people wanted it. And so it became hard to do the clinical trials in which they got a 50 percent chance of getting a placebo, because they didn’t want it. They’d heard the president say, ‘It’s a miracle drug,’ so they insisted on it.”
Hydroxychloroquine was later found to be dangerous, and an emergency authorization for the drug heralded by Mr. Trump was later rescinded.
Misrepresenting data. At a news conference Sunday announcing the emergency approval, President Trump and two of his top health officials misstated the effectiveness of the treatment. Public health officials and scientists have called for a correction.