Comparison of vaccine-induced thrombotic events between ChAdOx1 nCoV-19 and Ad26.COV.2.S vaccines

Hwang, Jimin; Lee, Se Bee; Lee, Seung Won; Lee, Min Ho; Koyanagi, Ai; Jacob, Louis; Tizaoui, Kalthoum; Yon, Dong Keon; Shin, Jae Il; Smith, Lee

Cerebral venous thrombosis (CVT) events have been reported after vaccination with adenoviral COVID-19 vector vaccines. This study aimed to compare the clinical presentations and courses of vaccine-induced thrombotic thrombocytopenia (VITT) between the two adenoviral vector vaccines, Ad26.COV.2.S (Janssen/Johnson & Johnson) and ChAdOx1 nCoV-19 (Astra-Zeneca). We found that CVT after Ad26.COV.2.S vaccination presents later with similar symptoms compared to CVT after administration of ChAdOx1 nCoV-19, albeit with more thrombosis and intracerebral hemorrhage, lower D-dimer and aPTT levels but similar mortality. These findings could help guide clinical assessment and management of CVT after COVID-19 vaccination.