CDC advisers to weigh limits on Johnson & Johnson vaccine because of continued blood clot issues

Vaccine advisers to the Centers for Disease Control and Prevention are meeting Thursday to weigh possible limits on the use of the Johnson & Johnson vaccine because of continued blood clot issues, mostly in young and middle-aged women, according to clinicians familiar with the agenda.

The single-dose vaccine has been linked to a rare and severe type of blood clot, which halted its use for 10 days in April as federal health officials looked more closely at six women who experienced the problem — the only known cases among more than 7 million people who received the vaccine in the United States at that time. One of the women died. The pause was lifted after an extensive safety review that determined the vaccine’s benefits outweighed the risks.

On Thursday, the Advisory Committee on Immunization Practices will be presented with new data that appears to show the rate of the clots in people who received the Johnson & Johnson shot has increased since April, although the problem is still rare. There have been about nine deaths related to the issue, according to a federal official familiar with the situation.