Europe – AstraZeneca COVID-19 vaccine: review of very rare cases of unusual blood clots continues

EMA’s safety committee (PRAC) is meeting today, Wednesday 31 March, in the context of its ongoing review of very rare cases of unusual blood clots associated with low numbers of platelets, in people vaccinated with AstraZeneca’s COVID-19 vaccine (now called Vaxzevria).

EMA convened an ad hoc expert group meeting on Monday 29 March to provide further input into the ongoing assessment. Independent external experts with a range of medical specialities, including haematologists, neurologists and epidemiologists, discussed specific aspects such as possible mechanisms, whether underlying risk factors could be identified and what additional data are needed to further characterise the observed events and the potential risk. The outcome of this meeting will be discussed by the PRAC and feed into its ongoing evaluation.

At present the review has not identified any specific risk factors, such as age, gender or a previous medical history of clotting disorders, for these very rare events. A causal link with the vaccine is not proven, but is possible and further analysis is continuing.

As communicated on 18 March, EMA is of the view that the benefits of the AstraZeneca vaccine in preventing COVID-19, with its associated risk of hospitalisation and death, outweigh the risks of side effects…