What is convalescent plasma therapy? Understanding the COVID-19 treatment endorsed by Trump

On Sunday, the U.S. Food and Drug Administration announced an emergency use authorization, or EUA, allowing the use of convalescent plasma therapy to treat those sick with COVID-19. CNN reports that the FDA said “known and potential benefits of [convalescent plasma therapy] outweigh the known and potential risks of the product.”

The EUA comes after weeks of President Trump claiming, without evidence, that the FDA was purposely slowing treatments for COVID-19 for political reasons. At the press briefing announcing the EUA for convalescent plasma therapy, Trump said there were officials at the FDA and Department of Health and Human Services who “can see things being held up and wouldn’t mind so much. It’s my opinion, very strong opinion, and that’s for political reasons.”

Political conspiracy theories aside, does convalescent plasma therapy actually work against COVID-19? Here are six things you need to know.

What is an EUA? It’s an emergency authorization for a specific treatment for a disease that has few other treatment options. EUA-approved treatments are thought to be generally safe, yet there isn’t enough hard data showing they are actually of benefit to the majority of people. In other words, the treatment probably won’t harm someone, but it’s not known if it will help them to a degree that is statistically meaningful.
What is plasma? Your blood is made up of cells and plasma. The plasma is the soupy liquid that the blood cells float in. This liquid also houses the antibody proteins a person produces when they get infected with a disease. The antibody proteins are part of the body’s way of fighting off that disease.
What is convalescent plasma therapy? It’s essentially a blood plasma injection. In convalescent plasma therapy, the blood plasma is taken from a donor who was once sick with COVID-19, whose blood now has lots of antibodies against the disease. That plasma is treated to identify the antibodies, and then it is injected into someone who currently has COVID-19 in an attempt to give their body the antibodies needed to fight the disease until their immune system can make its own antibodies.
Has convalescent plasma therapy been used to treat COVID-19 before? Yes. Convalescent plasma therapies are frequently used in fighting new diseases that have few other known treatments. The Guardian reports that over 64,000 people in the U.S. have been treated with convalescent plasma therapy to help fight COVID-19 infections.
Does convalescent plasma therapy work for COVID-19? Maybe. It depends on who you talk to. A Mayo Clinic study from August looked at 35,000 people. It found those who were not given convalescent plasma therapy as a treatment for COVID-19 had a mortality rate of 11.9% after four days. However, patients who were given convalescent plasma therapy as a treatment for COVID-19 within three days had a seven-day death rate of 8.7%. But that study has not been peer-reviewed.
Why issue the EUA for convalescent plasma therapy if more data on its effectiveness is needed? In short, it’s an election year. As Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, explained to CNN, he thought the FDA was pressured into the move by the White House. As Offit said, “I think what’s happening here is you’re seeing bullying, at least at the highest level of the FDA, and I’m sure that there are people at the FDA right now who are the workers there that are as upset about this as I am.”