In a hastily-called press conference Sunday evening, President Donald Trump and the heads of the Food and Drug Administration and Department of Health and Human Services announced what the president had touted as a “breakthrough” in treating the pandemic disease Covid-19. That breakthrough turned out to be a change in the bureaucratic status of convalescent plasma, a treatment made from the blood of people who have recovered from the disease—treatment that most people can already get, that at least 70,000 people have already received (and probably more like 100,000), and that despite the president’s assurances currently lacks solid evidence for its effectiveness.
“It is proven to reduce mortality by 35 percent. It’s a tremendous number,” Trump said at the press conference. “Based on this data, the FDA has made the determination the treatment is safe and very effective.” That last part isn’t actually true yet—without large-scale randomized controlled trials,