The Food and Drug Administration (FDA) together with the Centers for Disease Control and Prevention (CDC) is recommending a pause in the rollout of the Johnson & Johnson COVID-19 vaccine after several instances of severe blood clots in recipients.
According to the FDA, there have been six reported cases of the rare and severe type of blood clot in over 6.8 million Johnson & Johnson COVID-19 vaccine recipients.
"Right now, these adverse events appear to be extremely rare," the agency said on Twitter. "Treatment of this specific type of blood clot is different from the treatment that might typically be administered. CDC will convene a meeting of the Advisory Committee on Immunization Practices (ACIP) on Wednesday to further review these cases and assess their potential significance. FDA will review that analysis as it also investigates these cases."
However, until that review is completed, the FDA is "recommending this pause."
In a statement provided to Fox News, Johnson & Johnson said the "safety and well-being of people who use our products" remains the company's number one priority, and that it was aware of an "extremely rare disorder involving people with blood clots in combination with low platelets in a small number of individuals who have received our COVID-19 vaccine."
The company said that it has been "reviewing these cases with European health authorities," and that it had "made the decision to proactively delay the rollout of our vaccine in Europe." Additionally, the company said it has been working closely with medical experts and health authorities "and we strongly support the open communication of this information to healthcare professionals and the public."
In a statement posted to the agency's website, the FDA said the type of blood clot is called cerebral venous sinus thrombosis, and that it was seen in combination with low levels of blood platelets. All six cases involved women between the ages of 18 and 48, and symptoms occurred between six and 13 days post-vaccination.
The FDA said the pause in rollout would also "ensure that the health care provider community is aware of the potential for these adverse events and can plan due to the unique treatment required with this type of blood clot."
Johnson & Johnson had told the White House it would deliver 100 million doses of vaccine by the end of May, but faced a recent production blunder at a Baltimore plant and saw several mass sites shut down early over the last week due to potential adverse reactions.
In Georgia, eight people experienced lightheadedness, but officials could not rule out whether heat was a factor. In North Carolina, four people were taken to the hospital for reactions "consistent with known common side effects." In Iowa, three people experienced extreme lightheadedness, and in Colorado 11 people experienced dizziness and nausea.
The FDA said in a press conference Tuesday that it expected the pause to last several days as experts reveiwed available data.