Data show an overall rate of 3.23 cases of the blood clotting disorder per 1 million Johnson & Johnson doses administered, and the onset of symptoms for the individuals typically occurred one to two weeks after getting the vaccine. 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. Most people should get a Pfizer or Moderna COVID-19 vaccine, with the use of Johnson & Johnson limited to adults age 18 and older in instances where other vaccines are not accessible or clinically inappropriate.

Updated May 6, 2022