HALIFAX -- Nova Scotia has decided to stop giving the Oxford-AstraZeneca COVID-19 vaccine as the first dose effective immediately. "The decision to pause the use of AstraZeneca is based on science and the increased availability of mRNA vaccines," Dr. Robert Strang, Nova Scotia's chief medical officer of health, said during a news conference in Halifax on Wednesday afternoon. In a news release, the province noted that there was "an observed increase in the rare blood-clotting condition linked to this vaccine." The AstraZeneca vaccine has been linked to vaccine-induced immune thrombotic thrombocytopenia, or VITT, in other provinces. Strang said that there have been no cases of this in Nova Scotia.