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.

More information and advice for healthcare professionals and the public is available in the vaccine’s product information and the associated direct healthcare professional communication. Vaccinated people should be aware of the remote possibility of these very rare types of blood clots occurring. If they have symptoms suggestive of clotting problems as described in the product information, they should seek immediate medical attention and inform healthcare professionals of their recent vaccination.

EMA continues to work with the national authorities in the EU Member States to ensure that suspected cases of unusual blood clots are reported; these cases are being analysed in PRAC’s ongoing assessment.

Based on all the currently available data, PRAC is expected to issue an updated recommendation during its April plenary meeting (6–9 April).

The report describing the PRAC’s preliminary assessment of the reported cases of blood clots and conclusions is available.

Posted on the EMA website on 31 March 2021