18 March 2021 - EMA’s safety committee, PRAC, concluded its preliminary review of a signal of blood clots in people vaccinated with COVID-19 Vaccine AstraZeneca at its extraordinary meeting of 18 March 2021. 

The Committee confirmed that:

• the benefits of the vaccine in combating the still widespread threat of COVID-19 (which itself results in clotting problems and may be fatal) continue to outweigh the risk of side effects;
• the vaccine is not associated with an increase in the overall risk of blood clots (thromboembolic events) in those who receive it;
• there is no evidence of a problem related to specific batches of the vaccine or to particular manufacturing sites;
• however, the vaccine may be associated with very rare cases of blood clots associated with thrombocytopenia, i.e. low levels of blood platelets (elements in the blood that help it to clot) with or without bleeding, including rare cases of clots in the vessels draining blood from the brain.

Read EMA press release