OTTAWA -- Prime Minister Justin Trudeau says that while the order of who will be prioritized to receive COVID-19 vaccines—beyond the initial plan to immunize seniors and health care workers first—is still being sorted out, but the federal and provincial governments agree that there should be a cross-Canada “consensus” on the list.

With Health Canada now beginning its assessment of a fourth potential vaccine candidate — Johnson & Johnson’s — the prime minister said talks are ongoing with the provinces and territories about the “challenging ethical and societal” aspect of the country’s vaccine rollout.

Logistics of the rollout aside, governments and health care experts are having to weigh and decide who will be prioritized and what the eventual order of precedence will be for Canadians to line up and be vaccinated.

According to the preliminary guidance issued by the National Advisory Committee on Immunization, prioritization will be based on three factors: the state of the pandemic when the vaccine is available; the supply available and number of doses required; and the risk-benefit analysis of key populations such as those who are at higher risk for adverse outcomes if they contract the novel coronavirus.

Based on that advisory group’s preliminary guidance, the recommendation is that essential workers and others who face increased risks related to COVID-19 should be vaccinated against the disease before everyone else.

The subsequent order of who gets vaccinated next remains a largely open question, however, in the race to see 70 per cent of Canadians vaccinated by September.

“We talked about it with the provinces last week on our 22nd first minister's call, and there was a number of perspectives, but there seemed to be a consensus that we should all agree across the country on what that list looks like and make sure that it is applied fairly right across the country,” Trudeau told reporters on Tuesday.

“There are more conversations to come and we will keep Canadians have formed as we determine what that right order of priority is. Other elements of it is, certain vaccines might be more effective with certain populations versus others, and that's why the experts are going to be so important in making determinations around, what is the best path to move forward for our country,” said the prime minister.

Asked whether he anticipates being among the earliest groups to get vaccinated, Trudeau said that he’s “going to trust the experts to make the right determination of what the priority populations are.”

With files from CTV News’ Ryan Flanagan

More to come.