Age-Stratified Risk of Cerebral Venous Sinus Thrombosis After SARS-CoV-2 Vaccination.

BACKGROUND AND OBJECTIVES Cerebral Venous Sinus Thrombosis (CVST) as a part of the thrombosis and thrombocytopenia syndrome is a rare adverse drug reaction of SARS-CoV-2 vaccination. Estimated background rate of CVST with thrombocytopenia is 0.1 per million per month. We assessed the age-stratified risk of CVST with and without thrombocytopenia after SARS-CoV-2 vaccination. METHODS We estimated the absolute risk of CVST with and without thrombocytopenia within 28 days of first dose of four SARS-CoV-2 vaccinations, using data from the European Medicines Agency's EudraVigilance database (until 13 June 2021). As a denominator, we used data on vaccine delivery from 31 European countries. For 22.8 million adults from 25 countries, we estimated the absolute risk of CVST after the first dose of ChAdOx1 nCov-19 per age category. RESULTS The absolute risk of CVST within 28 days of first dose vaccination was 7.5 (95%CI 6.9-8.3), 0.7 (95%CI 0.2-2.4), 0.6 (95%CI 0.5-0.7) and 0.6 (95%CI 0.3-1.1) per million of first doses of ChAdOx1 nCov-19, Ad26.COV2.S, BNT162b2 and mRNA-1273, respectively. The absolute risk of CVST with thrombocytopenia within 28 days of first dose vaccination was 4.4 (95%CI 3.9-4.9), 0.7 (95%CI 0.2-2.4), 0.0 (95%CI 0.0-0.1) and 0.0 (95%CI 0.0-0.2) per million of first doses of ChAdOx1 nCov-19, Ad26.COV2.S, BNT162b2 and mRNA-1273, respectively. In recipients of ChAdOx1 nCov-19, the absolute risk of CVST, both with and without thrombocytopenia, was the highest in the 18-24 years age group (7.3 per million, 95%CI 2.8-18.8 and 3.7 per million, 95%CI 1.0-13.3, respectively). The risk of CVST with thrombocytopenia in ChAdOx1 nCov-19 recipients was the lowest in the age group≥70 years (0.2, 95%CI 0.0-1.3). Age <60 compared to ≥60 was a predictor for CVST with thrombocytopenia (incidence rate ratio 5.79; 95%CI 2.98-11.24, p