Cerebral vein thrombosis after four COVID-19 vaccines in Europe

Abstract

Cerebral vein thrombosis (CVT) with thrombocytopenia has been reported to EudraVigilance, the European Medicines Agency (EMA)’s database of suspected adverse drug reactions, after vaccination with four COVID-19 vaccines in Europe, according to findings of a study published in the Journal of Thrombosis and Haemostasis. EudraVigilance data (January–July 2021) were used to investigate the reporting rate of CVT (including intracranial sinus thrombosis and jugular vein thrombosis) after vaccination with the Pfizer-BioNTech COVID-19 vaccine [tozinameran], Moderna COVID-19 vaccine [CX-024414; mRNA-1273], AstraZeneca COVID-19 vaccine [AZD-1222; ChAdOx1-nCoV-19] and Janssen COVID-19 vaccine [Ad26-COV2-S]. The reporting rate of CVT was 21.60, 11.48, 5.63 and 1.92 per one million vaccinated-days for the AstraZeneca, Janssen, Moderna and Pfizer-BioNTech vaccine, respectively. For all four vaccines, CVT occurred with thrombocytopenia. The observed-to-expected ratio exceeded one for all four vaccines. Although the EMA has released a CVT alert only for adenoviral vector COVID-19 vaccines (AstraZeneca and Janssen), mRNA COVID-19 vaccines (Pfizer-BioNTech and Moderna) are also associated with CVT, to a lesser extent, concluded the authors. In accordance with the EMA statements, the benefits of vaccination against COVID-19 continue to outweigh the risks of side effects, including rare life-threatening thrombotic manifestations that appear to occur with all the four vaccines but with possible differences in frequency and mechanism that need further investigation, they said.