Agencies recommend pausing Johnson & Johnson vaccine

The U.S. Centers for Disease Control and Prevention and the Food and Drug Administration on Tuesday said they were investigating potentially dangerous blood clots in six women who received the single-dose COVID-19 vaccine. In the meantime, they recommended the country pause use of the shot. The reported complications appeared in women within two weeks of vaccination, and they also had low platelets in veins that drain blood from the brain. Federal officials want time to investigate and educate doctors on spotting and treating the clots. A CDC advisory committee plans to meet on Wednesday to discuss the cases.

Do other vaccines have similar problems? The blood clots are similar to those that European authorities said AstraZeneca’s COVID-19 vaccine may cause. Johnson & Johnson and AstraZeneca’s shots use an adenovirus to carry a protein that causes the body to make coronavirus antibodies, while the two leading vaccines used in the United States—from Pfizer-BioNTech and Moderna—use mRNA technology.

Dig deeper: Read Leah Hickman’s report in Vitals explaining how much different vaccines relied on aborted fetal cell lines.