Shannon Romano, a molecular biologist, came down with Covid late last March, about a week after she and her colleagues shut down their lab at Mount Sinai Hospital. A debilitating headache came first, followed by a fever that kept rising, and then excruciating body aches. “I couldn’t sleep. I couldn’t move,” she said. “Every one of my joints just hurt inside.”

It was not an experience she wanted to repeat — ever. So when she became eligible for the Covid-19 vaccine earlier this month, she got the shot.

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.