No shots...not getting in.

FWC wrote:
The problem I see with this, is how does the Canadian Border Service Agency, or any other foreign government access these databases?

bgum wrote:
In the US each state maintains a database containing name, date of first shot, date of second shot, name of manufacturer, and lot number.

This how the million dollar lottery has confirmed winners. The same could be used at borders to verify shot cards.

Probably just ask you to show the vaccine card.

Before you say it: Yes, some idiot could print up their own card and fake it but even among those against vaccinations, most won't take it to that level, so checking the card is 99% effective.

Keep in mind, this isn't a first case situation where they are trying to keep the virus out because they have zero cases. It's already there. These rules are only effective at slowing the spread. If they can eliminate 99% of new sources, that will be very effective at slowing the spread.