Ontario’s chief medical officer of health Dr. David Williams announced on Tuesday that the Ontario government is pausing the rollout of the 1st dose of the Oxford-AstraZeneca COVID-19 vaccine in the province out of an abundance of caution because of increased instances of an extremely rare and potentially fatal blood clotting linked to the shot. He added that the decision was also made based on the increased and reliable supply of Pfizer and Moderna as well as the downward trend of COVID-19 cases.