AstraZeneca Admits Its COVID Vaccine, Covishield, Can Cause Rare Side Effect Global pharmaceutical manufacturer AstraZeneca has admitted that its Covid-19 vaccine, developed by researchers from the Oxford University, can cause a rare side effect of blood clotting and low platelet count after immunisation. In India, the same vaccine, called Covishield and manufactured by the Pune-based Serum Institute, has been administered through 175 crore doses. Understandably, this raises questions as to the safety of the jab all of us took