AstraZeneca COVID-19 vaccine associated with risk of rare, potentially fatal blood clots

The Oxford-AstraZeneca COVID-19 vaccine is associated with a risk of “unusual blood clots with low blood platelets,” according to a new statement from the European Medicines Agency (EMA). These blood clots have been responsible for a total of 18 deaths.  

The EMA did emphasize that the benefits of receiving the AstraZeneca vaccine still outweigh the risks.

The EMA’s official safety committee, the Pharmacovigilance Risk Assessment Committee (PRAC), said that these blood clots should be listed as “very rare side effects” of the AstraZeneca vaccine going forward. The PRAC took “all currently available evidence” into consideration when making its decision, noting that cases of both cerebral venous sinus thrombosis (clots in the brain) and splanchnic vein thrombosis (clots in the abdomen) have been reported.

“EMA is reminding healthcare professionals and people receiving the vaccine to remain aware of the possibility of very rare cases of blood clots combined with low levels of blood platelets occurring within two weeks of vaccination,” according to the new statement. “So far, most of the cases reported have occurred in women under 60 years of age within two weeks of vaccination. Based on the currently available evidence, specific risk factors have not been confirmed.”

Symptoms that patients and providers should watch for include shortness of breath, chest pain, leg swelling and persistent abdominal pain. Severe, persistent headaches are also a sign that the patient should seek medical help immediately.

The EMA has been examining this issue at length for weeks now. Multiple countries, including Denmark, Norway and Iceland, first temporarily paused the use of the AstraZeneca vaccine due to blood clot concerns in the second week of March. Germany, France and Spain all also temporarily suspended use of the vaccine just days later.

The EMA has evaluated and supervised the safety of medicines in the European Union for more than 25 years. Click here for more information on the agency.

Michael Walter
Michael Walter, Managing Editor

Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.

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