Abstract
This case series reports six patients (four men and two women; median age, 38 years; interquartile range, 26-48 years) who presented with vaccine-induced thrombocytopenia and thrombosis beginning 3-26 days after receiving the first dose of the ChAdOx1 nCoV-19 (AstraZeneca) vaccine for COVID-19. The patients were admitted to a general hospital between 9 and 31 days after the first dose. All patients had strongly detected antiplatelet factor 4 antibodies and severe thrombosis. Laboratory features included thrombocytopenia and elevated d-dimer levels. Thrombotic events were predominantly venous; two patients had arterial or mixed arterial and venous thrombosis. All patients recovered after receiving intravenous immunoglobulin and nonheparin-based anticoagulation. © RSNA, 2021 An earlier incorrect version appeared online. This article was corrected on August 18, 2021.