Covid-19 and adverse effects after vaccination and SARS-Cov-2 Infection

WHAT IS ALREADY KNOWN ON THIS TOPIC

Rare thrombocytopenia and thromboembolic events have occurred after covid-19 vaccination
After these rare events, several countries restricted the use of the ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccine

WHAT THIS STUDY ADDS

Increased risk of thrombocytopenia, venous thromboembolism, and other rare arterial thrombotic events were found after a first dose of the ChAdOx1 nCoV-19 vaccine and of arterial thromboembolism and ischaemic stroke after a first dose of the BNT162b2 (Pfizer-BioNTech) vaccine

Increased risk of cerebral venous sinus thrombosis was found after a first dose of both vaccines—a week later with BNT162b2 than with ChAdOx1 nCoV-19
The risks of these outcomes after vaccination were much lower than those associated with SARS-CoV-2 infection in the same population

BMJ 2021;374:n1931 http://dx.doi.org/10.1136/bmj.n1931