There is no data proving vaccine passports work, said Canada's chief public health officer Dr. Theresa Tam. Tam noted its impact on vaccination rates had not been studied yet by the Public Health Agency of Canada, reported Blacklock's.

"It’s something we should pay close attention to and study," said Tam. "That also helps other jurisdictions should they want to make these kinds of decisions."

Four provinces – British Columbia, Manitoba, Ontario and Quebec – have issued orders requiring proof of vaccination to access non-essential public services like restaurants and hockey arenas. Alberta will also make proof of vaccinations available to its residents on September 16.

Dr. Tam said 7.3 million Canadians are not yet fully vaccinated, including five million who have declined the first immunization.

The Health Agency figured 69 percent of eligible residents are fully vaccinated in the four provinces with vaccine passports. Vaccination rates in provinces without mandates average 67 percent.

"In your opinion, do vaccine mandates or vaccine passports have any kind of impact on boosting vaccination rates?" asked a reporter.

"We are watching carefully," replied Tam. "We don’t have good evaluation or statistics except that provinces individually have said, I think in the media, that they saw an increase in uptake."

"Is there data indicating what does work?" asked a reporter.

"Some of it is just trust-building, getting influencers, youth influencers, people who can get to social media, TikTok in particular," replied Tam.

She encouraged local health authorities to consider operating mobile clinics through workplaces, adding: "What I’m interested in is an actual study of the full range of approaches."

"But the question before that, which is, do locally implemented requirements for vaccines to access non-essential services, for example work? That remains to be seen."

The Liberal Party, in its September 1 campaign platform Forward For Everyone, advocated an Act of Parliament "to ensure every business and organization that decides to require proof of vaccination from employees and customers can do so without fear of a legal challenge." Currently, compulsory vaccination to access public services would breach the Privacy Act, according to Privacy Commissioner Daniel Therrien.

Canadians who have declined a COVID shot are "more than just being wrong because everyone’s entitled to their opinion, they are putting at risk their own kids and they’re putting at risk our kids as well," said Prime Minister Justin Trudeau on August 31.

"What about my choice to keep my kids safe?" said Trudeau. "What about our choices to make sure we’re getting through this pandemic as quickly as we can?"

"We’ll stand firm on our commitment," said Trudeau, adding: "We’ll protect businesses that mandate vaccinations from unjustified lawsuits."

During Thursday's leadership debate, he added, "the unequivocal leadership that we've shown as a government on making sure that everyone gets vaccinated is what's going to get us [through the pandemic]. We cannot rebuild the economy until we get through this pandemic."