Consider that last September amid the fourth wave of the virus, seven-in-ten Canadians (70%) said they would support a vaccine passport in their community to require residents to show proof of inoculation to enter larger public spaces; this concept is now supported by one-in-four (25%).
The most disgusting rule was in Quebec where the government mandated vaccine passports for stores like Walmart and Costco in January of 2022. The backlash was immediate and rule lasted less than a month.
Now, an incredible majority is against vaccine passports. I bet the major reason for this drastic shift in opinion is that the definition of "fully vaccinated" keeps changing. Many people went along with the two initial shots plus a booster in the winter. They've likely realized the absurdity of the whole situation as they're told to get the boosters till infinity. In short, they're against the passports because they no longer qualify as fully vaccinated.