On Sunday, the FDA and President Trump announced emergency authorization to use convalescent plasma to treat COVID-19. The plasma comes from the blood of people who have recovered from the virus. It's the yellow fluid left after red blood cells have been removed. Research has shown it can help people fighting the illness.

The announcement was treated with great excitement. The initial information said that the plasma could reduce the deaths of people hospitalized by a third. But experts say we need more research to know how effective it is. It's easy to get excited about a treatment, but, at these early stages, nothing is "a sure thing."

Now, only a couple of days later, the FDA's Commissioner Stephen Hahn is apologizing for stating it could save 35 percent of people who received the treatment. The research he was citing hasn't been peer reviews, didn't have a placebo or control group and had people receiving the plasma at different times. In short: without control, those numbers cannot be trusted.

The researchers also never said plasma could save 35 percent of people who received it. They said it could lower mortality rates by 35 percent relative to what they were. While that is a third less, that doesn't mean that 35 out of 100 people were now going to survive. It means that people were 35 percent less likely to die than they otherwise would be.

Dr. Hahn tweeted a comment, "I have been criticized for remarks I made Sunday night about the benefits of convalescent plasma. The criticism is entirely justified. What I should have said better is that the data show a relative risk reduction not an absolute risk reduction."

While a tweet and acknowledgment is something, an apology and clarification would be better. The tweet doesn't help clear up the confusion his incorrect statement made.

None of this means convalescent plasma doesn't help people. It does appear to aid people's recovery! However, at a time when we need clear medical advice, the commissioner of the FDA should be thoroughly briefed before making statements.

The emergency authorization hasn't been revoked. Thus far, no serious adverse effects have been seen, and the research does show promise. Even if it doesn't save 35 percent of people, lowering the risk by 35 percent is a useful tool in the fight against COVID-19. They may revoke the authorization if the treatment is found to be ineffective. Until then, we'll keep our eye on the results.