BRUSSELS — The calls began in December, as the United States prepared to administer its first batches of Covid-19 vaccine. Even then, it was clear that the European Union was a few weeks behind, and its leaders wanted to know what they could learn from their American counterparts.

The questions were the same, from President Emmanuel Macron of France, President Ursula von der Leyen of the European Commission, and Alexander De Croo, the prime minister of Belgium.

“How did you do it?” Dr. Moncef Slaoui, the United States vaccine czar, recalled them asking on the calls. “And what do you think we missed?”

TORONTO — As frustration mounts in Canada at the leaden weight of lockdowns and the glacial pace of vaccinations, a consortium of some of the country’s largest companies has launched a rapid testing program with the aim of protecting their 350,000 employees and publishing a playbook for businesses across Canada on how to reopen safely.

The program is believed to be the first of its kind among the Group of 7 industrialized nations, and has already attracted the attention of the Biden administration.