Update following MHRA and EMA decisions on AstraZeneca’s COVID-19 vaccine

Today the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) and European Medicines Agency (EMA) completed their assessment of extremely rare blood clotting events with low platelets from over 34 million people vaccinated with AstraZeneca’s COVID-19 vaccine in the UK and EU.

Updates to the UK and EU labels for the vaccine have been requested by the regulators. Neither agency identified any risk factors, such as age or gender, or a definite cause for these extremely rare events. However, they came to the view that these events have a possible link to the vaccine and requested they be listed as an extremely rare potential side effect.

Overall, both of these reviews reaffirmed the vaccine offers a high-level of protection against all severities of COVID-19 and that these benefits continue to far outweigh the risks.

AstraZeneca has been actively collaborating with the regulators to implement these changes to the product information and is already working to understand the individual cases, epidemiology and possible mechanisms that could explain these extremely rare events.

In addition, the World Health Organisation (WHO) today said that, based on current information, a causal relationship is considered plausible but is not confirmed, adding that further specialised studies are needed to fully understand the potential relationship between vaccination and possible risk factors.

Furthermore, the WHO noted that, whilst concerning, the events under assessment are very rare, with low numbers reported among the almost 200 million individuals who have received the AstraZeneca COVID-19 vaccine around the world.

Press Contact

Mónica Solórzano Lobo- monica.solorzano1@astrazeneca.com

Government Affairs, Patients and Communications Lead, CAMCAR - Central America and Caribbean 


AstraZeneca is a global, science-led biopharmaceutical company that focuses on the discovery, development and commercialisation of prescription medicines, primarily for the treatment of diseases in three therapy areas - Oncology, Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca operates in over 100 countries and its innovative medicines are used by millions of patients worldwide. Please visit https://www.camcar.astrazeneca.com/en/ and follow the Company on Twitter @AstraZenecaCAR.