COVID-19 Vaccine-Induced Thrombotic Thrombocytopenia: A Case Series

Vaccine-induced thrombotic thrombocytopenia is a life-threatening prothrombotic syndrome that has been associated with two adenoviral vector-based coronavirus disease 2019 (COVID-19) vaccines. Although it remains a rare disorder with relatively low incidence, awareness of this condition is crucial given the ongoing vaccination programs of millions around the world. In this case series, we report four cases of vaccine-induced thrombotic thrombocytopenia, diagnosed at Queen Alexandra Hospital, Portsmouth, United Kingdom. We also review the mechanism of this syndrome, its clinical presentation, diagnosis, and course of treatment with emphasis on the role of therapeutic plasma exchange.