News

U.S. Lifts Pause of Johnson & Johnson Vaccine—Here's What Changed

boxes of janssen johnson & johnson vaccine

Jon Cherry / Stringer / Getty Images

Key Takeaways

  • The FDA and CDC have lifted the pause on the Johnson & Johnson COVID-19 vaccine in the United States.
  • The vaccine will now feature a warning label about the risk of blood clots.
  • Investigators were able to confirm that the combination of blood clots and low blood platelet counts after vaccination is extremely rare—only 15 total cases were identified out of 8 million Johnson & Johnson doses.
  • The side effect has not been seen in Pfizer and Moderna vaccine recipients.

The Johnson & Johnson COVID-19 vaccine can now be administered again in the United States. On Friday, April 23, the Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) announced that they were lifting the 10-day pause on the vaccine after a thorough safety investigation into the rare side effect of blood clots.

The official decision came about two hours after an advisory committee to the CDC recommended lifting the pause without any new restrictions on who can get the vaccine.

In a joint news release, the organizations concluded that "the available data show that the vaccine’s known and potential benefits outweigh its known and potential risks in individuals 18 years of age and older."

In a statement, CDC director Rochelle P. Walensky, MD, MPH, said that the CDC's "vaccine safety systems are working. We identified exceptionally rare events—out of millions of doses of the Janssen COVID-19 administered—and we paused to examine them more carefully.

Walensky added that "as we always do, we will continue to watch all signals closely as more Americans are vaccinated."

While this is good news for COVID-19 vaccine supply in the U.S., some committee members involved in the decision expressed that they would have preferred that the resumption came with clearer guidance about who is most at risk for the rare side effect and what the alternative options are.

Why Was the Vaccine Paused?

The specific risk investigated during the pause involved six reports of cerebral venous sinus thrombosis (CVST)—a blood clot that prevents blood from draining out of the brain—paired with low blood platelet counts (thrombocytopenia).

Together, the two conditions are being referred to as thrombosis-thrombocytopenia syndrome (TTS). All six cases occurred among women between the ages of 18 and 48. They developed symptoms 6 to 13 days after receiving the Johnson & Johnson vaccine.

During the pause, the FDA and CDC evaluated vaccine side effect reports that had been submitted to the Vaccine Adverse Event Reporting System (VAERS). They also reviewed medical literature and compared reactions to the AstraZeneca vaccine—which is authorized for use in other countries and similar in design to Johnson & Johnson.

The review revealed nine other cases of TTS within 15 days of vaccination with the Johnson & Johnson vaccine in the U.S., bringing the total to 15 cases.

All of the TTS cases were in women between the ages of 18 and 59.

The review showed that the incidence of TTS is still extremely rare—15 cases out of 8 million administered doses. Health officials say that the risk of experiencing the side effect is very low.

Furthermore, the benefits conferred by a single-dose vaccine option outweigh the 0.00012% risk of TTS. In clinical trials, the vaccine demonstrated 85% protection from serious COVID illness and 100% protection from COVID-related death.

The pause also gave the FDA and CDC the opportunity to reach out to healthcare providers across the country to discuss what these adverse events look like and how to treat them.

Unlike other types of blood clots (including blood clots caused by birth control, which have received much attention over the past two weeks as a point of comparison), CVST can't be treated with common blood thinners like heparin because of the associated low blood platelet counts seen in these patients.

Symptoms to Look For

The CDC and FDA are advising Johnson & Johnson vaccine recipients who develop any or all of the following symptoms within three weeks of vaccination to contact a healthcare provider:

  • Severe headache
  • Abdominal pain
  • Leg pain
  • Shortness of breath

What Happens Now?

Vaccination sites can begin administering the Johnson & Johnson vaccine again as soon as Saturday, April 24. Currently, there are about 10 million J&J doses available in the U.S.

On Tuesday, April 20, the European Medicines Association also lifted a pause on the Johnson & Johnson vaccine, moving forward with a new warning label.

The only change from before the pause involves a revised fact sheet for healthcare providers and a revised fact sheet for vaccine recipients and caregivers. The fact sheet includes information about the recently identified risk.

No New Recommendations for Younger Women

Prior to Friday's decision, some experts wondered whether the Johnson & Johnson vaccinations would resume in all groups, or if women of reproductive age (who were most affected by TTS) would still be encouraged to seek out Pfizer or Moderna vaccines instead.

In the U.K. where AstraZeneca's vaccine (which has also been linked to rare blood clots) is available to anyone 18 to 29 years old, a different vaccine brand is offered when possible.

While the CDC's Advisory Committee on Immunization Practices (ACIP) seems to have considered this approach in the U.S., ultimately, the J&J vaccine will still be available to all adults.

The panel voted 10 to 4 to recommend the use of the J&J vaccine, and importantly, the four dissenters were not opposed to resuming the vaccine's use. They were advocating for more clarity about who is most at risk for adverse events.

“I have no problem with the continued availability of this vaccine,” said ACIP member Pablo J. Sánchez, MD, a professor of pediatrics at Ohio State University, during the publicly-streamed meeting. Sánchez voted against the motion. “But I think that if we just make a blanket recommendation knowing the risks that seem to have biologic possibility and severity, I think we have to have stronger language and make sure people are informed appropriately.”

ACIP member Sarah S. Long, MD, a professor of pediatrics at Drexel University College of Medicine, also voted against the motion, citing frustration with the lack of guidance about other vaccine options for people who fall into the most affected age group.

“I did not object to the recommendation; I objected to the lack of any kind of guidance from us," said Long. “This is an age group most at risk [for TTS] that is getting this vaccine predominantly to save other people’s lives and morbidity, not their own. I think we have a responsibility that they know this, and if they chose to be vaccinated with this anyhow, we want to respect that choice. I am very sorry that we haven’t chosen to put upfront that this is unique, it is clustered and it is almost certainly related to the vaccine, and there are options."

Is the Damage Already Done?

While the FDA and CDC emphasize that the Johnson & Johnson vaccine is safe and effective, all of the buzz the pause caused and the serious nature of the side effects—however rare—have affected how people feel about the vaccine.

The negative news about side effects comes alongside growing reports of Johnson & Johnson vaccine manufacturing issues at a plant in Baltimore, Maryland.

A poll from Axios shows that while 77% of respondents support the pause, 54% are unwilling to take the Johnson & Johnson vaccine in the future (regardless of renewed federal approval). The rates are especially worrisome among the vaccine-hesitant, over half of whom reported becoming more hesitant as a result of the TTS news.

Encouraging those who are hesitant to get the vaccine is crucial to achieving herd immunity. We need at least 70% of the population to get fully vaccinated to curb the pandemic.

While the latest data from Verywell's vaccine sentiment tracker shows that 73% of respondents are vaccinated or plan to get vaccinated against COVID-19, about 10% still aren't sure—a figure that's remained largely unchanged for weeks.

A single-dose COVID-19 vaccine that does not require extremely cold temperatures for storage is an extremely useful tool for boosting vaccination rates and getting us closer to herd immunity, especially in hard-to-access areas—but people have to be willing to take it.

For now, CDC data shows that there is still plenty of Pfizer and Moderna vaccines available for those who prefer them. However, because not all vaccine sites stock multiple COVID-19 vaccine brands, it may take some shopping around to get the dose you want, when you want it.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Food and Drug Administration (FDA). FDA and CDC Lift Recommended Pause on Johnson & Johnson (Janssen) COVID-19 Vaccine Use Following Thorough Safety Review. Updated April 23, 2020.

  2. Johns Hopkins Medicine. Cerebral venous sinus thrombosis (CVST).

  3. Centers for Disease Control and Prevention (CDC). COVID-19 vaccinations in the United States. Updated April 23, 2021.

  4. Food and Drug Administration (FDA). Vaccines and Related Biological Products Advisory Committee Meeting. Updated February 26, 2021.