Thrombosis with Thrombocytopenia Syndrome

Thrombosis with thrombocytopenia syndrome (TTS) is a rare syndrome that involves acute venous or arterial thrombosis and new onset thrombocytopenia in patients with no recent known exposure to heparin. TTS has been reported in the U.S. after receipt of Janssen COVID-19 Vaccine. The FDA’s EUA for Janssen COVID-19 Vaccine now includes a warning that rare clotting events might occur after vaccination, primarily among women aged 18–49 years.


Page last reviewed: November 16, 2021