Document - A very rare new type of adverse event called Thrombosis with Thrombocytopenia Syndrome (TTS), involving unusual and severe blood clotting events associated with low platelet counts, has been reported after vaccination with COVID-19 Vaccines Vaxzevria and Covishield. A specific case definition for TTS is being developed by the Brighton Collaboration1. This will assist in identifying and evaluating reported TTS events and aid in supporting causality assessments.
