OTTAWA -- With more than half of Canadians now at least partially vaccinated against COVID-19 and bookings opening for all who are eligible, the federal government says the country will be well-placed to start “moving forward on second doses” in June.

While Canada is now sitting third among G20 countries when it comes to doses administered per capita, the country still trails behind when it comes to the number of eligible citizens who are fully vaccinated. This is a result of governments opting to take the advice of the National Advisory Committee on Immunization to delay second shots by up to 16 weeks, to more widely spread what in early 2021 was a limited supply of vaccines.

On Tuesday, facing continued questions about the state and timing of Canada’s mass vaccination effort, Prime Minister Justin Trudeau said he remains “absolutely confident” that every person who is eligible and willing to be vaccinated will be, by the end of September.

“We will have more than enough doses in Canada by the end of June to give a first dose to every Canadian who wants one, and second doses will continue to ramp up through June and into the summer,” Trudeau said, imploring all who are eligible to book their first shots now.

Right now, with most provinces scheduling peoples’ second doses for up to four months after their first, some people who have booked June appointments for their first doses have been given October appointments for their second.

As CTVNews.ca has previously reported, some provinces have said they planned to shorten the interval between doses once first shots were completed and the supply was there. Federal health officials have also suggested that most people will likely not be waiting four months between doses.

“There will be more than enough doses,” Trudeau said Tuesday, though it remains up to each region to decide whether and when to move up second shot appointments.

On Tuesday, Quebec Health Minister Christian Dube told reporters that second doses will be accelerated in that province, citing the boost in supply from Pfizer, which has to-date delivered more than 17 million doses to Canada with 2.4 million more doses per week expected through June.

Still, the government is fielding questions from the federal Conservatives over why more isn’t being done to facilitate cross-border vaccination efforts, allowing Canadians in U.S. border towns to travel south to receive their second shots potentially earlier than they will be offered at home.

“If vaccines are so widely available here, then there wouldn't be waitlists, there wouldn't be delays, and there wouldn't be a four-month gap between shots,” said Conservative MP Glen Motz during question period.

'MILLIONS' OF MODERNA DOSES COMING: ANAND

While Moderna has not yet publicly confirmed its Canadian delivery schedule for future COVID-19 vaccine doses, Procurement Minister Anita Anand said that after talking to the company on Tuesday morning, Moderna intends “to deliver millions and millions of doses in the month of June.”

“The supplier has communicated to us that millions of doses are expected to be delivered in June, and that the first shipment will come in the first part of June,” she told reporters.

As for where things stand with AstraZeneca, Anand said that her department still anticipates receiving one million doses “in late June,” while the Johnson & Johnson shots in Canada and any future shipments of that one-shot vaccine will remain “on hold” until Health Canada weighs in on whether they meet quality assurance standards.

As of Tuesday, 23 million COVID-19 doses have been distributed across Canada, with 21 million of those doses administered.

“Canada remains very much on track to receive vaccines for eligible Canadians to receive a first shot by the end of June, and for all Canadians to be fully vaccinated by the end of September,” Anand said.