Assessing a Rare and Serious Adverse Event Following Administration of the Ad26.COV2.S Vaccine
See and colleagues present a case series of patients with cerebral venous sinus thrombosis (CVST) following vaccination with the Ad26.COV2.S vaccine manufactured by Janssen/Johnson & Johnson. These cases were identified through the Vaccine Adverse Event Reporting System (VAERS), a national vaccine safety surveillance program of the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA). The 12 patients—all women aged 18 to 59 years—developed symptoms beginning 6 to 15 days after vaccination, along with declines in platelet counts (with nadirs ranging from 9 to 127 ×103 /μL), and clinically severe clotting, including CVST (12 patients), and non-CVST thrombosis (8 patients). Of the 12 patients, 10 required intensive care, 7 also had intracerebral hemorrhage, and 3 have died. In addition to the 12 patients with CVST with thrombocytopenia described in this case series, at least 3 patients without CVST but meeting diagnostic criteria for thrombosis with thrombocytopenia syndrome (TTS) have been reported to VAERS (as of April 21, 2021), all in women aged 18 to 59 years (median age, 37 years). Of the 15 total patients, 3 have died.