- Study compares risks of thrombocytopenia and thromboembolic events following ChAdOx1 nCov-19 (Oxford-AstraZeneca), BNT162b2 mRNA (Pfizer-BioNTech) vaccination, and SARS-CoV-2 (Covid-19) infection
- Study shows increased risk of thrombocytopenia and venous thromboembolism with ChAdOx1 nCoV-19, and increased risk of arterial thromboembolism following BNT162b2 mRNA
- Risks of these adverse events were however much higher following SARS-CoV-2 infection
- Study authors fully independent from Oxford vaccine developers
Writing in the British Medical Journal (BMJ), they detail the findings from over 29 million people vaccinated with first doses of either the ChAdOx1 nCov-19 ‘Oxford-AstraZeneca’ vaccine or the BNT162b2 mRNA ‘Pfizer-BioNTech’ vaccine. They conclude that with both of these vaccines, for short time intervals following the first dose, there are increased risks of some haematological and vascular adverse events leading to hospitalisation or death.