The post-vaccination blood clotting and low blood platelet levels seen in a small number of people who received the Johnson & Johnson COVID-19 vaccine has not been seen in any Americans who got shots from Pfizer or Moderna, a U.S. official said Tuesday.
Dr. Peter Marks, director of the Food and Drug Administration’s Center for Biologics Evaluation and Research, told reporters on a call that “at this time, we’ve not found any reports of cerebral venous sinus thrombosis combined with thrombocytopenia” among those who received a Pfizer or Moderna shot.
