The U.S. is recommending a "pause" in administrating the single-dose Johnson & Johnson COVID-19 vaccine to investigate reports of potentially dangerous blood clots. In a joint statement Tuesday, the CDC and FDA said it was investigating clots and reduced platelet counts in six women post-vaccination. All six were women between the ages of 18 and 48; one died and a second is hospitalized in critical condition. More than 6.8 million doses of the J&J vaccine have been administered in the U.S.