As a new wave of the SARS-COV-2 epidemic overwhelms Europe, the vaccine from the Anglo-Swedish laboratory AstraZeneca has come under the spotlight, suspected of having serious thrombotic adverse drug reactions (ADRs)[1]. The first reports of coagulation problems were described in Austria, Italy and the Nordic countries. An unusual number of cerebral venous sinus thrombosis associated with platelet deficiency (thrombocytopenia) and bleeding was reported in Germany. This association was found in 7 cases by 15 March 2021 (date of suspension in Germany) with a temporal association consistent with AstraZeneca vaccination. The 7 affected individuals were women aged 20-50 years; 6 had cerebral venous sinus thrombosis, occurring 4-16 days after vaccination; 3 died. The World Health Organization (WHO) and the European Medicines Agency (EMA) were quick to point out the benefits-risks balance remained in favour of the vaccine, and that there was currently no proven causeand-effect relationship [1].

In France, over 1,923 million people received the AstraZeneca vaccine between 6 February and 25 March 2021 [2]. A total of 7,439 ADRs were reported of which 91 cases of serious thromboembolic events, including 9 cases of cerebral venous sinus thrombosis, 2 cases of splanchnic venous thrombosis and 1 case of combined stroke/pulmonary embolism/splanchnic venous thrombosis in the context of disseminated intravascular coagulation [2]. These 12 cases of thrombosis of the large veins were atypical in their location (mainly cerebral, but also digestive) and may be associated with thrombocytopenia or coagulation disorders [2]. These cases occurred mostly in women, within a median of 9 days after vaccination in patients mainly under 55 years of age (9 patients vs. 3 over 55 years of age), with no particular history identified to date, apart from oral contraception in 4 cases, associated with a protein C/S defi-ciency in one fifth and obesity in 1 case. Lymphadenopathy is regularly described. Among them, 4 people died[2]. The very atypical character of these thromboses, their common clinical picture and the homogeneous time of occurrence lead the monitoring committee to confirm the very ra re occu rrence of this thrombotic risk in people vaccinated with Astr aZeneca vaccine [2].