COVID-19 cases linked to variants of concern continues to rise in B.C., one expert warns that more restrictions may be needed to stop the variant spread.Sally Otto, a University of British Columbia professor who has done COVID-19 modelling, said cases involving variants of concern, such as B.1.1.7, which was first identified in the U.K., have doubled every week over the last month and a half.Otto described the province’s vaccination rollout and the rise in COVID-19 variants as a horse race.“The variants are like a thoroughbred and our vaccines are like a workhorse,” she said.Vaccination efforts have the potential to overtake the spread of variants by summertime, she said, but there is a risk of a sharp rise in cases in the short term.“We’re.