The US is recommending a "pause" in using the single-dose Johnson & Johnson COVID-19 vaccine to investigate reports of potentially dangerous blood clots.
In a joint statement Tuesday, the Centers for Disease Control and Prevention and the Food and Drug Administration said they were investigating unusual clots that occurred 6 to 13 days after vaccination.
The clots occurred in veins that drain blood from the brain and occurred together with low platelets. All six cases were in women between the ages of 18 and 48; there was one death.
The reports appear similar to a rare, unusual type of clotting disorder that European authorities say is possibly linked to another COVID-19 vaccine not yet cleared in the U.S., from AstraZeneca. More than 6.8 million doses of the J&J vaccine have been administered in the U.S., the vast majority with no or mild side effects.