CALGARY—A return to a somewhat normal summer as COVID-19 restrictions are eased is putting a strain on Canada’s blood supply. Several provinces have started lifting restrictions—most notably Alberta, British Columbia and Saskatchewan—and demand is up as a result. “As provinces slowly open up, there’s some return to normal activities. Hospital demand is increasing,” said Tracy Smith, the Prairies and Northwest Territories donor relations director for the Canadian Blood Service. “You can imagine that they are trying to catch up with some of the backlogs, some of those surgeries that were put on hold during the pandemic. They’re trying to get those in … (and) blood products are becoming more in demand.” The need for blood products tailed off dramatically 16 months ago as the pandemic brought travel to a near standstill and all but the most critical surgeries were cancelled. At the same time, Canadian Blood Services wasn’t able to …