TAPPER: We're back with our health lead now. And it's been one week since Johnson & Johnson paused its coronavirus vaccine trial, and we still do not have detailed information as to why. We do know that a participant in the trial became ill, but Johnson & Johnson and the FDA refuse to answer questions about the exact nature of that illness. Joining us now, CNN senior medical correspondent Elizabeth Cohen. Elizabeth, transparency is very important. What have you learned?</s>ELIZABETH COHEN, CNN SENIOR MEDICAL CORRESPONDENT: Jake, not only do we not know those details that you mentioned about what happened to this patient, what kind of illness. There are even more basic and straightforward things that the company isn't telling us and that the FDA says they are legally prohibited from telling us. For example, we don't know the answer to the basic question, did this recipient get a vaccine or did they get a placebo? We don't know that. Johnson & Johnson says they don't know. But experts I have talked to says that that seems -- that we should know that by now. It's been more than a week. The second question is, is this the first pause for the trial? It's possible that this is not the first pause. When you ask that question, you don't get an answer. And to talk a little bit about why this pause is so important, I want to point out that there are only four phase three clinical trials for COVID vaccines going on in the U.S. right now. Let's take a look at them. Pfizer and Moderna both started July 27. And they have not paused. They are ongoing. AstraZeneca started August 31 and paused September 9, so, as you can see, didn't go on for very long. The J&J trial started September 23 and paused October 12. So, they also did not go on for very long.
Reason For Pause in Some Vaccine Trials?