Johnson & Johnson Vaccine Hits Pause In U.S. Distribution : Consider This from NPR The Centers for Disease Control and Prevention and the Food and Drug Administration announced a recommended pause in use of Johnson & Johnson's single-use COVID-19 vaccine, while the agencies investigate reports of a rare but serious blood clot in six people.

The pause comes at a time when public health officials face the growing challenge of vaccine hesitancy, as NPR's Geoff Brumfiel reports.

NPR's Tamara Keith and Pien Huang explain the science behind the pause, and how it's occurring at a challenging moment for the Biden administration.

Additional reporting in this episode comes from NPR's Allison Aubrey.

The NPR Politics Podcast is also covering the Johnson & Johnson vaccine pause. Listen on Spotify or Apple Podcasts.

In participating regions, you'll also hear from local journalists about what's happening in your community.

Email us at

The J & J Pause, Explained — And What It Means For The U.S. Vaccination Effort

  • Download
  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript


Scientists are trying to emphasize the numbers.


ANTHONY FAUCI: This is a really rare event. If you look at what we know so far, there have been 6 out of the 6.85 million doses, which is less than 1 in a million.

KELLY: As Dr. Anthony Fauci explained at the White House on Tuesday after reports of six people developing rare but potentially serious blood clots, the CDC and FDA are recommending a pause in the use of Johnson & Johnson's COVID vaccine.


FAUCI: We are totally aware that this is a very rare event. We want to get this worked out as quickly as we possibly can. And that's why you see the word pause.

KELLY: Fauci emphasized a few other things. One, anyone who got the shot a month ago or longer faces very low risk, and their vaccine is no less effective. Two, Pfizer and Moderna, the other vaccines currently authorized for use in the U.S., work in a very different way than the J&J shot. No such issues have been reported with those vaccines.


FAUCI: The next question is one that we're all obviously aware of. What impact is this going to have about people's attitudes about vaccines in general?

KELLY: Fauci went back to the numbers. According to the White House, of the 190 million shots given so far in the U.S., the J&J vaccine makes up less than 5%.


FAUCI: So you're talking about tens and tens and tens of millions of people have received vaccine with no adverse effect and the fact that a pause was done I think just as a testimony to how seriously we take safety.

KELLY: CONSIDER THIS - public health leaders have to hope that will sound persuasive because the Johnson & Johnson pause comes just as vaccine demand shows signs of slowing down.

From NPR, I'm Mary Louise Kelly. It's Tuesday, April 13.


KELLY: It's CONSIDER THIS FROM NPR. Here's what we know about those blood clots that occurred in six people who received the Johnson & Johnson vaccine. All of them were women ages 18 to 48. One of the women died. Another is in critical condition. Now, the type of blood clot that they developed is known as CVST.


PETER MARKS: Cerebral venous sinus thrombosis, or CVST.

KELLY: Dr. Peter Marks of the FDA said on Tuesday, CVST could be the result of a very rare immune response to the J&J shot that also involves a low level of platelets in the blood. Marks said scientists speculate...


MARKS: This is an immune response that occurs very, very rarely after some people receive the vaccine. And that immune response leads to activation of the platelets and these extremely rare blood clots.

KELLY: Similar concerns over rare blood clots have been raised with the Oxford-AstraZeneca vaccine, which has been widely used around the world, especially in Europe. The EU also paused use of that vaccine temporarily last month. Here in the U.S., one of the big concerns that scientists have is that CVST blood clots require a different kind of treatment.


MARKS: The issue here is that if one administers the standard treatments that we as doctors have learned to give for blood clots, one can actually cause tremendous harm or the outcome can be fatal.

KELLY: That difference in treatment is something officials mentioned repeatedly when they explained the pause, saying they want to give the health care community time to get up to speed. The pause also gives time for a CDC committee to review data and potentially issue new recommendations about the use of the vaccine or who should get it. And, of course, officials will monitor for more instances of clots in people just recently vaccinated.


MARKS: But I cannot speculate on how many more we'll learn of. Hopefully, it's just going to be a few.

KELLY: The FDA and CDC scientists who briefed reporters Tuesday emphasized they expect this pause to be temporary, possibly a matter of days. Officials also said anyone who has received the J&J shot within the last few weeks - stay alert for symptoms of severe headache, abdominal pain, leg pain or shortness of breath.

The J&J pause comes at a challenging time in the U.S. vaccination effort. Already this week, there were signs that demand for vaccines in the U.S. is slowing down.


ALI MOKDAD: Hesitancy is going to be a big problem for us in May, June simply because we will have more vaccines than people are willing to take the vaccine.

KELLY: That's Ali Mokdad at the University of Washington. Like a growing number of public health experts, he is forecasting that in the next month or two, most people in the U.S. who want a vaccine will have gotten one, meaning the U.S. vaccine campaign will have to shift and target people who have yet to make it a priority. In some places, that shift is already happening.


CLAIRE HANNAN: We're just kind of reaching that point where supply is ahead of demand in some areas.

KELLY: Claire Hannan is with the Association of Immunization Managers. She points to some areas of the country where there are efforts under way to reach out directly to people who have not gotten a shot.


HANNAN: In Alaska, they're actually going door to door. And in North Dakota, they're getting their providers to record messages, to send out little videos to their patients, you know, encouraging the vaccine, stating that they've gotten the vaccine.

KELLY: The effort here, of course, is all about herd immunity, which is going to require a large number of Americans to be vaccinated. But in a recent NPR/Marist poll, nearly 1 in 3 Americans said they were either unsure about COVID vaccines or that they would refuse one if offered. And while hesitancy is highest among Republican men, it spans all demographics.


KOLINA KOLTAI: It's literally everyone. And it says that, like, everyone knows someone in their life who is not willing to get vaccinated.

KELLY: Kolina Koltai studies vaccine misinformation at the University of Washington.


KOLTAI: For the first time in a very long time, we have everyone deciding this decision, whether or not they're going to vaccinate themselves as an adult. And so we're all becoming susceptible to anti-vaccine narratives that could be promoted in ways that are beyond anti-vaccination communities.


KELLY: So back to that question you heard at the top from Dr. Anthony Fauci - how will news of the J&J pause affect public perception of COVID vaccines? NPR's Tamara Keith and Pien Huang have been digging into that question and into more of the science behind the pause. Pien is a health reporter on NPR's science desk, and Tam covers the White House. The three of us spoke on Tuesday afternoon.


KELLY: Hey, there, you two.



KELLY: So, Pien, you start. What do we know about the woman who died?

HUANG: Yeah. So there is a listing in the CDC's Vaccine Adverse Events database. And it appears to describe the woman who developed these complications and died after getting the J&J vaccine. The report describes a 45-year-old woman in Virginia. She got the vaccine in early March. And a week after getting the shot, she got a really bad headache and ended up going to the hospital for it. She had blood clotting and low platelet count and died about two weeks after getting the vaccine.

KELLY: Tam, let's bring you in. What does the White House have to say about all this?

KEITH: The White House coronavirus coordinator, Jeff Zients, and Dr. Anthony Fauci both came to the regularly scheduled press briefing today, which tells you that they are taking this very seriously. They made it clear that the FDA and CDC made this decision to call for the pause without consulting the White House. And Zients says that's exactly how it should be, that science should be leading the way.


JEFF ZIENTS: I think it's important that, you know, we have here the FDA, and the FDA is the gold standard for ensuring the safety and the effectiveness of the vaccines. And today's action, I think, is clear evidence that they're taking every step necessary to ensure the American people have clear and transparent information.

KEITH: But there is no question that this is inconvenient for the White House for any number of reasons. Running a successful vaccine rollout is important for the president politically. Of course, it is also incredibly important from the perspective of public health and the economy. And as if to remind us of how different this approach is from former President Trump, the former president sent out a statement today slamming the FDA and CDC and the Biden administration and saying that they should have stepped in and not let this happen, that there shouldn't be a pause for just so few people experiencing the side effects.

The Biden team is betting that letting the scientists lead - even if it is politically inconvenient, you know, not publicly badgering them or complaining about the decision - will help build trust that there isn't interference - political interference and that the only priority of the FDA and CDC is keeping people safe.

KELLY: Although, there were already parts of the country where there actually was enough vaccine supply, but the big challenge remained persuading people to go get the shots. What is the risk that this development is going to scare people off?

KEITH: You know, it's not clear. But people who specialize in public health think that this transparency will be important. That said, yeah, this absolutely could create a temporary cloud of uncertainty. In theory, though, if J&J is restarted, there should be confidence that it is safe. But this is another bad headline for a vaccine that has already had its share of bad headlines, including problems at a production facility in Baltimore.

So, you know, it's not a coincidence that the White House is emphasizing instead that they have lots of doses of the Pfizer and Moderna vaccines available and that it is safe. And they are saying that with or without the J&J challenges, there is a lot of work to be done to convince a share of the public that any of these vaccines are safe and that it is worth the effort to get vaccinated.

KELLY: Yeah, so many challenges ahead - Pien, I'm going to give you the last word. In terms of what comes next, what happens with this pause, do we know how long this pause might last?

HUANG: Yeah, well, it's not completely clear right now how long it's going to last. Dr. Anthony Fauci said earlier today that that might be a few days, a few weeks. But currently, the FDA and the CDC are both independently reviewing the risks. And tomorrow, the CDC's vaccine advisory committee is meeting, and they'll be discussing what's known about these cases and voting to update the recommendations for how the Johnson & Johnson vaccine is used.

FDA officials have said that while it's not completely clear what's causing the problem, it does appear similar to some blood clotting cases in Europe, which was linked to a similar COVID vaccine made by the drug company AstraZeneca. That also appeared to be happening in younger women, so some countries ended up putting age restrictions around who gets that vaccine. So something like that could happen here. And it's the type of thing the CDC group will consider on Wednesday.

KELLY: That's NPR's Pien Huang and Tamara Keith.

And if you want to hear more on the politics of Tuesday's vaccine pause and what it means for the Biden administration, Tam and her colleagues over at the NPR Politics Podcast have an episode for you. We've got a link in the notes of this episode.

It's CONSIDER THIS from NPR. I'm Mary Louise Kelly.

Copyright © 2021 NPR. All rights reserved. Visit our website terms of use and permissions pages at for further information.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.