TORONTO -- With Canada expected to receive fewer doses of the COVID-19 vaccine than initially anticipated, the country’s vaccine advisory committee has narrowed its guidance on which groups should be prioritized for vaccination first.

In mid-November, the National Advisory Committee on Immunization (NACI) – a group of medical, pharmaceutical and public health experts who make recommendations to the Public Health Agency of Canada (PHAC) on vaccines and vaccine-related issues – updated their preliminary guidance on key populations for early COVID-19 immunization.

In the preliminary guidance, released nearly a month ago, the NACI recommended that four groups should be prioritized to receive the first doses of the vaccine.

These four groups included those at high-risk of severe illness and death from the disease, including “older populations,” those most likely to transmit COVID-19 to those at high risk, essential workers, and those whose living and working conditions put them at an increased risk.

Under the revised recommendations, however, the NACI tightened up its list of who should be prioritized for vaccination. Now, the advisory committee has identified these specific groups as the ones who should considered for early immunization.

  • Residents and staff of long-term care, assisted living, retirement homes, and chronic-care hospitals.
  • Individuals of advanced age (starting with 80 years and older and expanding by five-year increments to age 70 years as doses become available)
  • Health care workers, considering exposure risk
  • Indigenous communities

The groups listed above were not listed in any specific order, according to the NACI.

In an email to CTVNews.ca on Wednesday, NACI committee chair Dr. Caroline Quach-Thanh confirmed the refined guidance was because of the limited number of vaccine doses expected early on.

PHAC confirmed in mid-November that Canada could receive six million vaccine doses by the end of March 2021, but that is dependent on the completion of regulatory approvals by Health Canada first.

And while the NACI has advised the government on vaccines for decades, their refined list of priority groups is just a recommendation. Canada’s provinces and territories will be tasked with making the ultimate decisions on the distribution of the vaccine.

It also remains unclear how vaccine doses will be divided among the provinces and territories, and if certain regions will be prioritized over others.

On Tuesday, Prime Minister Justin Trudeau said talks between the federal government and provinces and territories on the vaccine rollout were ongoing.

“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,” Trudeau said.

Later that day, Health Minister Patty Hajdu said provinces will be able to refine their prioritization lists based on regional demographics.

“At the end of the day it is the provinces who deliver health care and it is the provinces who will decide on the priority populations, and of course, we’re working closely to make sure that we have co-ordination across the country, and that we agree on the principles, which in fact we have, we have a shared set of principles,” Hajdu said.

With files from CTVNews.ca’s Rachel Aiello