CDC Postpones Decision on Johnson & Johnson COVID-19 Vaccine

The pause in the distribution of J&J vaccines will continue as the CDC reviews more data on the rare blood clots found in six women who had received the vaccine.

Apr 15, 2021 at 9:39 am
click to enlarge The pause on Johnson & Johnson COVID-19 vaccines continues. - Photo: CDC, Unsplash
Photo: CDC, Unsplash
The pause on Johnson & Johnson COVID-19 vaccines continues.

The Centers for Disease Control and Prevention (CDC) says that the agency needs more data to fully assess any risk from the Johnson & Johnson/Janssen (J&J) COVID-19 vaccine.

The 13 members of the CDC’s Advisory Committee on Immunization Practices (ACIP) met for about four hours Wednesday to discuss the cases of unusual, severe blood clotting found in six women who had received the J&J vaccine. 

>About six to 13 days after getting the J&J vaccine, six women ages 18-48 developed cerebral venous sinus thrombosis (CVST) — a rare blood clot in the brain — alongside a low number of platelets, which are tiny blood cells that bond to stop the bleeding when parts of the body are damaged.

The combination of CVST and a low platelet count is extremely rare, experts say. 

During the meeting, the CDC reviewed data on CVST, but because most existing data does not also include information about low platelet count, the agency postponed recommending specific actions and will continue its review.

About 6.8 million people in the United States have received the J&J vaccine, and these six women are the only people known to have experienced this type of clotting.

During a briefing with Ohio Gov. Mike DeWine this week, Dr. Susan Koletar, director of Ohio State University’s division of infectious diseases at the Wexner Medical Center, said that most people receiving the vaccine will not experience this.

“There’s a lot of thought and work being done, probably as we speak, looking at specific immune reactions or autoimmune reactions that occur and affect the platelets, which allow blood to clot,” Koletar said. “And it’s an interesting and rare event where there’s situations where the platelets are low but there’s still all this clotting. The clots that have been seen have been more rare than others.”

The Vaccine Adverse Event Reporting System (VAERS), where providers and physicians note issues of concerns nationally, alerted federal agencies to the blood clots cases.

The CDC also discussed limiting the J&J vaccine to certain age groups or genders in which CVST is less likely, but ultimately postponed all recommendations until after further investigation.

The CDC and Food and Drug Administration (FDA) jointly recommended Tuesday that vaccine providers pause administering the J&J vaccine while they investigate the issue. Most states, including Ohio and Kentucky, have taken that recommendation.

Since adjourning Wednesday’s ACIP meeting, the CDC continues to recommend the pause in distribution to review the data and provide education to health providers and vaccine administrators because the CVST clots must be treated differently from traditional blood clots.

“Usually, an anticoagulant drug called heparin is used to treat blood clots. In this setting, administration of heparin may be dangerous, and alternative treatments need to be given,” the CDC said. “(Pausing distribution) is important, in part, to ensure that the health care provider community is aware of the potential for these adverse events and can plan for proper recognition and management due to the unique treatment required with this type of blood clot.”

The J&J COVID-19 vaccine received emergency use authorization in February. Two other vaccines from Pfizer and Moderna were authorized in December.

Unlike the Pfizer and Moderna vaccines that require two doses several weeks apart, the J&J vaccine needs only a single dose, making it effective for college students, people without homes, people who are in corrections facilities, minority groups and people who are less likely to return for a second dose of the other vaccines.

Pfizer and Moderna vaccines are unaffected by the J&J pause and continue to be considered safe and effective.

The CDC recommends seeking urgent medical care if you develop the following collection of symptoms up to three weeks after receiving the J&J vaccine:

severe headache,


new neurologic symptoms,

severe abdominal pain,

shortness of breath,

leg swelling,

tiny red spots on the skin (petechiae), or

new or easy bruising

Read the CDC's slides from Wednesday’s meeting. Learn more about the J&J vaccine. Report concerns to VAERS.