On Sunday, the Food and Drug Administration issued an “emergency use authorization” for blood plasma to treat COVID-19. The decision was well within the agency’s remit but nevertheless generated instant controversy. President Donald Trump had just attacked the “deep state” at the FDA for holding up COVID-19 treatments; the next day, the normally staid and careful agency was cheerleading plasma as “another achievement in administration’s fight against pandemic.” The FDA commissioner, Stephen Hahn, boasted that plasma could save 35 out of 100 treated COVID-19 patients if the data held up—a claim so grossly misleading, he had to recant it.
The limited evidence available suggests that infusing patients with the antibody-rich plasma of survivors is, at best, incrementally effective. One study found that patients who received plasma within three days of a COVID-19 diagnosis had marginally better outcomes than those who received it later. There is no randomized, controlled trial yet comparing patients who were given plasma with those who were not.
Even so, plasma does technically meet the low bar for “emergency use authorization,” or EUA, which is a much looser standard than formal FDA approval. The 2004 law that created the EUA process requires that “it is reasonable to believe that the product may be effective.” The flexibility is helpful in emergencies, but it can also backfire if exercised too often, too carelessly, or too politically. In the EUA mechanism, experts and former FDA officials fear, the Trump administration has found a soft spot vulnerable to political pressure, which could be especially intense as the agency begins reviewing data for COVID-19 vaccines.