COVID-19 vaccines and thrombosis with thrombocytopenia syndrome.

Lai, Chih-Cheng; Ko, Wen-Chien; Chen, Chih-Jung; Chen, Po-Yen; Huang, Yhu-Chering; Lee, Ping-Ing; Hsueh, Po-Ren

INTRODUCTION To combat COVID-19, scientists all over the world have expedited the process of vaccine development. Although interim analyses of clinical trials have demonstrated the efficacy and safety of COVID-19 vaccines, a serious but rare adverse event, thrombosis with thrombocytopenia syndrome (TTS), has been reported following COVID-19 vaccination. AREAS COVERED This review, using data from both peer-reviewed and non-peer-reviewed studies, aimed to provide updated information about the critical issue of COVID-19 vaccine-related TTS. EXPERT OPINION : The exact epidemiological characteristics and possible pathogenesis of this adverse event remain unclear. Most cases of TTS developed in women within 2 weeks of the first dose of vaccine on the receipt of the ChAdOx1 nCoV-19 and Ad26.COV2.S vaccines. In countries with mass vaccination against COVID-19, clinicians should be aware of the relevant clinical features of this rare adverse event and perform related laboratory and imaging studies for early diagnosis. Non-heparin anticoagulants, such as fondaparinux, argatroban, or a direct oral anticoagulant (e.g., apixaban or rivaroxaban) and intravenous immunoglobulins are recommended for the treatment of TTS. However, further studies are required to explore the underlying mechanisms of this rare clinical entity.