Updated Statement on Covid-19 Vaccines and Thrombosis From Thrombosis Canada

March 19, 2021 11:00 UTC


Thrombosis Canada seeks to reassure the public regarding blood clot risk and COVID-19 vaccines


TORONTO--(BUSINESS WIRE)-- Thrombosis Canada has reviewed recent reports from the United Kingdom and Europe relating to the SARS-CoV-2 (COVID-19) vaccine made by AstraZeneca and the development of a very rare type of thrombosis (blood clots) that is associated with thrombocytopenia (low blood platelets).

It is the view of Thrombosis Canada that, based all available evidence, people who receive the AstraZeneca vaccine are not at increased risk of developing blood clots when compared with the general population.

However, the AstraZeneca vaccine may be associated with extremely rare cases of blood clots that occur in the brain (called cerebral sinus vein thrombosis) and are associated with low blood platelets. These blood clots were found to occur in 1 in 250,000 to 1 in 500,000 people who received the vaccine.

By comparison, people who have COVID-19 are at much higher risk of developing blood clots, which occur in about 1 in 20 people who are in hospital with COVID-19 and in about 1 in 100 people who have COVID-19 but are not in hospital.

“Thrombosis Canada strongly recommends that people receive vaccinations for COVID-19, including the vaccine made by AstraZeneca” says Thrombosis Canada President, Jim Douketis, “that’s what we are telling the many patients who have been asking us because of the reports from Europe. The benefits of preventing blood clots and other disease caused by COVID-19 far outweigh any possible risks, which we consider very low.”

Thrombosis Canada further strongly recommends that the following groups of people receive vaccinations for COVID-19:

1) people who have had a previous blood clot
2) people with a family member who has developed a blood clot
3) people with a hereditary clotting tendency (e.g., factor V Leiden mutation)
4) people who are receiving blood thinner medications

Thrombosis Canada is dedicated to education and awareness of thrombotic disease. We encourage the public to be aware of the signs and symptoms of thrombosis (blood clots) by accessing our resources at https://thrombosiscanada.ca/resourcepage/patient-family-information/


Please note that the recommendations contained herein must be viewed as general guidelines based on current knowledge. Their application must be adapted to individual patients. Thrombosis Canada assumes no responsibility or liability arising from any error or omission or from the use of any information contained herein. You must not rely on the information in this document as an alternative to medical advice from your doctor or other professional healthcare provider.

@ThrombosisCan (www.ThrombosisCanada.ca)

Thrombosis Canada comprises a membership that includes the most eminent and internationally recognized thrombosis experts globally. Members have made many significant contributions to the body of knowledge in vascular medicine and disseminated that knowledge through hundreds of peer-reviewed publications, as well leading the development of international clinical practice guidelines.


David Airdrie
Executive Director
Thrombosis Canada


Source: Thrombosis Canada

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