WASHINGTON — On Tuesday both the Food and Drug Administration and Centers for Disease Control and Prevention  are recommending a “pause” in the administration of Johnson & Johnson’s single-dose COVID-19 vaccine to review blood clot cases.

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The agencies announced in a statement that the CDC will convene a meeting of the Advisory Committee on Immunization Practices on Wednesday to review six cases of “a rare & severe type of blood clot” in people who received the vaccine. The FDA will then review 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,” Dr. Anne Schuchat, principal deputy director of the CDC, and Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said in the statement.

As of Monday, over 6.8 million doses of the single-dose vaccine had been administered across the country.

The handful of cases the FDA and CDC are investigating occurred in women and involved a blood clot called cerebral venous sinus thrombosis, which was seen alongside low levels of blood platelets, according to their statement. Symptoms were seen 6 to 13 days after vaccination in the women, who were between the ages of 18 and 48.