Canada once was hailed as a success story in dealing with the coronavirus pandemic, faring much better than the United States in deaths and infections because of how it approached lockdowns. But the trade-dependent nation has lagged on vaccinating its population because it has had to rely on the global supply chain. Washington hasn’t allowed the hundreds of millions of vaccine doses made in America to be exported, and Canada has had to turn to Europe and Asia. Prime Minister Justin Trudeau’s government bet on seven different vaccines manufactured elsewhere and secured advance purchase agreements — enough to get 10 doses for each of Canada’s 38 million people. While acquiring them has proven difficult, deliveries are ramping up.