European Medicines Agency’s safety committee, PRAC, concluded its preliminary review of a signal of blood clots in people vaccinated with COVID-19 Vaccine AstraZeneca at its extraordinary meeting of March 18, 2021.
According to the statement published on the EMA’s website, “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”.
Thus, the vaccine is not associated with an increase in the overall risk of blood clots (thromboembolic events) in those who receive it. However, the vaccine may be associated with very rare cases of blood clots, including rare cases of clots in the vessels draining blood from the brain (CVST), even though there is no evidence of a problem related to specific batches of the vaccine or to particular manufacturing sites.
“These are rare cases – around 20 million people in the UK and EEA had received the vaccine as of March 16 and EMA had reviewed only 7 cases of blood clots in multiple blood vessels (disseminated intravascular coagulation, DIC) and 18 cases of CVST. A causal link with the vaccine is not proven, but is possible and deserves further analysis,” the agency said.
The agency will continue close safety monitoring of reports of blood clotting, and further studies will be instituted to provide more laboratory data as well as real-world evidence.
“The PRAC will undertake additional review of these risks, including looking at the risks with other types of COVID-19 vaccines (although no signal has been identified from monitoring so far),” the statement concluded.