U.S. and European health officials are scrutinizing the Johnson & Johnson (J&J) and AstraZeneca COVID vaccines for possibly causing blood clots and related blood disorders in vaccine recipients.
But evidence is mounting that the Pfizer and Moderna vaccines cause similar adverse reactions — and U.S. regulatory officials were alerted to that fact as far back as December 2020.
Read More: Scientists Warn Pfizer, Moderna Vaccines May Cause Blood Clots, Too