Wu: She had been tweeting about this, and I knew she would provide some really balanced perspective here. First things first: She has gotten the vaccine. There is really no undoing that. But she’s not spending all of her time worrying about getting a clot—partly because that won’t affect whether or not she does—but also because these cases have so far been really, really rare. I don’t think we yet have enough information to say they’re going to appear in exactly X percentage of people, but it’s probably going to be an extraordinarily low number.
Higgins: What are the symptoms to look for in that very rare case?
Wu: There’s a list that the CDC and FDA put out. They said if you develop severe headaches, abdominal pain, leg pain, or shortness of breath within three weeks of your injection, reach out to your health-care provider. But that is going to be the next level up from the expected side effects that some people might get within the first couple of days after getting their injection, which might include a mild headache. So there’s a little bit of subjectivity there, but hopefully people are just keeping an eye out in those three weeks. That’s the critical window we’re looking at here.
Hamblin: Do you think this has been handled correctly? Do you think pausing Johnson & Johnson for everyone was the right move?
Wu: That’s a tricky question to answer, but I think I lean on the side of “yes.” Imagine if the CDC and FDA had waited until it was 20 cases, or 30 cases, or 100 cases … [they] would have gotten questions about why they didn’t pause it when it was just six and we could have prevented 94 more cases.
I think they saw a signal and not just a random cluster of blood clots [that] all looked so similar in this demographic slice of the population. And so they acted quickly. This pause could just be a matter of days to get clarity and make sure that people are aware and looking out for it. I wouldn’t be surprised if more cases come up because we now know to look for it. [But] they are not hoping to permanently derail this vaccine.
Hamblin: Do you think this pause—assuming it doesn’t pan out to be over a major risk factor and Johnson & Johnson gets back online—will, over time, lead to vaccine hesitancy of the sort that we’ve seen with AstraZeneca in Europe? How concerned are you about it exacerbating what we’ve already seen in the U.S.?
Wu: I am concerned about this, but I don’t want to jump to conclusions about how hesitancy will be affected. It’s so tricky because exacerbating hesitancy can occur in a multitude of ways. One is: People hear something negative about the vaccine and they feel less good about taking it. Another is that experts conceal something about the vaccine and the public feels like they’re not being trusted with the relevant information.
The CDC and FDA are in a bit of a “damned if you do, damned if you don’t” situation, but I’ve been really impressed with how a lot of experts have tried to communicate the situation as clearly as they can, and really stress the point that we can make better-informed decisions with this information being publicly out there.