Ontario will no longer offer first doses of the AstraZeneca COVID-19 vaccine due to an increase in reports of rare blood clots. The announcement was made by Ontario’s Chief Medical Officer of Health Dr. David Williams on Tuesday afternoon. “This decision was made out of an abundance of caution,” Williams said. The AstraZeneca vaccine was being offered to individuals aged 40 and up at numerous pharmacies across the province. According to Chief Health Protection and Emergency Preparedness Officer Dr. Jessica Hopkins, the risk of thrombotic thrombocytopenia (VITT) associated with the vaccine in Ontario is one in 60,000. Hopkins later clarified that as of May 8, eight Ontarians have developed blood clots related to the vaccine. “At this point in time, and given that we’re seeing the overall case numbers of COVID going down, and an increase in the safety signal at a population level, it makes sense to pause AstraZeneca, because the risk of severe outcomes with VITT shouldn’t be underestimated.” Williams added that the decision to pause is also based on the increased and reliable supply of these other vaccine options.