Health Canada concludes AstraZeneca benefits outweigh blood clot risks by Michael Ranger Last Updated Apr 14, 2021 at 10:56 am PDT Health Canada says a new and extremely rare blood clotting syndrome may be linked to the AstraZeneca vaccine, but the agency says the benefits of the shot still far outweigh any risks. The agency says there is no evidence showing certain people are more at risk than others and the vaccine will remain authorized for all adults in Canada. Chief Medical Advisor Dr. Supriya Sharma says Health Canada will be updating the label for the vaccine to warn of the possibility of blood clots.