Pause on Johnson & Johnson COVID vaccine expected to be ‘a matter of days,’ CDC and FDA say

The Centers for Disease Control and Prevention and the Food and Drug Administration say the pause on the Johnson & Johnson COVID vaccine will last a “matter of days” as experts review the reports of rare blood clotting in a small group of women who were vaccinated

Federal regulators paused administration of the J&J vaccine “out of an abundance of caution” due to reports of six cases of a “rare and severe” blood clot, called cerebral venous sinus thrombosis.

The clots occurred in women roughly six to 13 days after getting the J&J vaccine, said Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, during a virtual call with reports Tuesday morning.

One of the patients died, and another is in critical condition, Marks said.

“Right now, these events appear to be extremely rare,” he said.

Anne Schuchat, the CDC’s principal deputy director, said the pause is so the federal agencies and carefully deliberate and consider next steps. Federal officials are now alerting state health officials, pharmacies and other health care providers to ensure they know about the pause and how to evaluate and report on any similar reactions in people who’ve received the J&J vaccine.

Officials said the bloods clotting symptoms include severe headaches, abdominal pain, leg pain and shortness of breath — symptoms that are different, they stressed, from those that some people develop as part of the immune response a few days after getting the COVID vaccine. Those flu-like symptoms, occurring a day or two after receiving the shot, are not generally of concern.

“We don’t have a definitive cause yet,” Marks said. But officials postulate the clots may be a result of an immune system response that occurs “very rarely,” leading to activation of blood platelets.

Marks said the background rate for cerebral venous sinus thrombosis is between 2 and 14 per million people in individuals with normal blood platelet counts.

But it’s the combination of low blood platelets, the blood clots and the J&J vaccine that officials flagged as being of concern. They said the clot symptoms occurred on average nine days after vaccination with the J&J shot.

“The real combination is it’s their occurrence together that makes a pattern, and that pattern is very, very similar to what was seen in Europe with another vaccine, so we have to take the time to make sure we understand this complication and address it appropriately,” Marks said.

The CDC said it will convene a meeting of the Advisory Committee on Immunization Practices on Wednesday to further review the cases and assess their potential significance. The FDA will look at that analysis as it also investigates the cases.

“Until that process is complete, we are recommending a pause in the use of this vaccine out of an abundance of caution,” the agencies said in a joint statement. “This 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.”

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