WASHINGTON — Canada is once again allowing U.S. citizens and permanent residents back into the country, provided they’ve been fully vaccinated against COVID-19.

After 17 long months, a ban on non-essential travel across the Canada-U.S. border was finally eased at midnight, although the Americans have yet to lift their own limits on Canadian travellers.

Eligible visitors must live in the U.S. and have allowed 14 days to pass since receiving a full course of a Health Canada-approved vaccine.

They are also required to show proof of a negative molecular test for COVID-19 that’s no more than 72 hours old and to use the ArriveCAN app or online web portal to upload their vaccination details.

Fully vaccinated travellers who have recovered from the disease and are otherwise eligible to enter Canada can show proof of a positive molecular test taken between 14 and 90 days prior to crossing the border.

Denis Vinette, vice-president of the travellers branch of the Canada Border Services Agency, says the agency learned a lot when fully vaccinated Canadian citizens were allowed to return under similar conditions last month.

Vinette says about half had to be turned away during the first week because they hadn’t received one of the four vaccines approved by Health Canada, or had not waited the full 14 days after their last shot.

Canada has approved four vaccines: Pfizer-BioNTech, Moderna, the Oxford-AstraZeneca shot, also known as Covishield, and the single-dose Johnson & Johnson option. All except AstraZeneca have been approved and widely deployed in the U.S.

The U.S., for its part, has been mum on when it might begin to ease its own restrictions on non-essential Canadian travellers at land crossings. Air and sea travellers are exempt, though passengers by rail, ferry and pleasure boat are not.

The White House did say last week that it is exploring whether to require discretionary visitors from outside the country to be fully vaccinated when the time comes to ease restrictions, although it remains unclear whether that discussion specifically includes Canadian travellers.

A labour dispute between the federal government and Canadian border agents was resolved promptly last week, easing fears of extensive delays. But Vinette says the screening process is still going to take time, which means travellers may have to wait a little longer to clear customs.

“We’re just asking folks to be patient.”

The federal government is currently planning to allow vaccinated visitors from outside the U.S. to return to Canada for non-essential reasons as of Sept. 7.