Who is at risk for the blood clotting disorder associated with the Johnson & Johnson vaccine?

The risk of having an adverse reaction to the vaccine is very low. Data show an overall rate of 3.8 cases of the blood clotting disorder per 1 million Johnson & Johnson doses administered. Risk varies by age and gender, but data show that the risk of developing a rare blood clotting disorder after receiving the Johnson & Johnson vaccine is highest for women age 30-49.

Updated December 17, 2021