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BSI response to announcement from EMA & MHRA on AstraZeneca/Oxford vaccine and blood clots

18 March 2021

The European Medicines Agency (EMA) and the Medicines Healthcare products Regulatory Agency (MHRA) have today both issued announcements on the safety of the AstraZeneca/Oxford COVID-19 vaccine following the decision by several countries to pause the rollout in order to assess rare reports of people getting blood clots after receiving the vaccine. In response the British Society for Immunology has issued the following statement.


Dr Doug Brown, Chief Executive of the British Society for Immunology said:

“When developing a new vaccine, the two most important factors are safety and effectiveness. All vaccines have to go through rigorous clinical trials before they are approved for use and they are then monitored during subsequent rollout by the appropriate safety authorities, which in the UK is the Medicines Healthcare products Regulatory Agency (MHRA).  The approved COVID-19 vaccines in the UK have all been through this thorough process.  

“Over the last few days, a number of countries decided to pause the rollout of the AstraZeneca/Oxford COVID-19 vaccine to double check that having the vaccine is not linked to any cases of blood clots. These reports can sound worrying but we need to put the risk into perspective. As we all know, people fall ill for a multitude of reasons. As has happened in this case, it is right the medicines regulators review the evidence to work out what the cause is behind the rare reports of blood clots and whether it is linked to having been given the vaccine or not. We must remember that COVID-19 is a disease that can have serious consequences in its own right, including the development of coagulation problems.   In the case of the AstraZeneca/Oxford vaccine, the European Medicines Agency have concluded the vaccine is safe and effective and recommend the continuation of the vaccine rollout, a viewpoint backed up by the UK regulator, the MHRA.

“Vaccines are our route out of this pandemic. Whilst safety is always the foremost concern, this episode shows that the monitoring systems are working as they should.  Vaccination is the safest and most effective way to protect yourself from falling ill with COVID-19.”


You can read the full comment from the MHRA here

You can read the full comment from the EMA here

You can find out more information on COVID-19 vaccines in the British Society for Immunology's "Guide to Vaccinations for COVID-19". We also have a number of additional helpful resources on COVID-19 vaccinations including Q&A videos that you can find in our Coronavirus information hub