The European Medicines Agency (EMA) safety committee has concluded that the AstraZeneca vaccine’s proven efficacy in preventing hospitalization and death from COVID-19 outweighs the extremely small likelihood of developing blood clots.
25 cases in 20,000,000 people who received the vaccine
These are rare cases, with only 7 cases of blood clots in multiple blood vessels (disseminated intravascular coagulation, DIC) and 18 cases of clots in the vessels draining blood from the brain (CVST), in around 20 million people in the UK and EEA had received the vaccine as of March 16. The EMA review has found no causal link.
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 (CVST).
