Canada’s Chief Public Health Officer Dr. Theresa Tam is advising Canadians to continue to wear a mask, regardless of varying jurisdictional guidelines, as the country sees a resurgence of COVID-19 cases.

Speaking to reporters during a pandemic update on Tuesday, Tam also underlined the need to get boosted with a third COVID-19 vaccine dose to prevent against severe outcomes from the illness.

“Let me just emphasize all across Canada, doesn't matter where you are, it’s very likely that the Omicron variant, the BA.2 sub-lineage is spreading quite widely in your community. So doesn't matter where you are in Canada right now, I would advise getting that booster shot, masking and improving ventilation,†she said.

Tam added that a masking mandate might eliminate individual “guesswork,†but acknowledged that provincial public health authorities are trying to encourage good habits without forcing them on people.

“I think in different communities, depending on the context, the social cohesion, and other variables, each of those policies might work better under different circumstances. But I think people are keen to see and trust that the population are able to employ those layers of protection,†she said.

Asked whether the definition of “fully vaccinated†needs to change from two to three doses, Tam said it is an “ongoing discussion†but maintained the importance of getting a third shot.

“I think the message today is get up to date with your vaccination which includes a booster for the eligible population for all extensive purposes, that's 18 plus and [it] also can be offered to adolescents. So that is the most important message,†she said.

There’s been a gradual rise in COVID-19 cases nationwide since the end of March. However, officials say this was expected after some provinces lifted public health restrictions, including masking requirements and proof of vaccination.

As testing rates have decreased, local authorities have been tracking virus prevalence through municipal wastewater testing. At a national level, Tam said officials are trying to make more of that data publically available.

“We are trying to provide that information about the wastewater testing sites on a website, but I know we can do more as we are beginning to escalate the benefit of this tool ... Wastewater data right now covers just over 60 per cent of the population. We're aiming to do better, to try to get to that 80 per cent coverage, but it's not the easiest thing to interpret,†she said.

According to data tracked by CTVNews.ca, approximately 32.4 million first doses of the COVID-19 vaccine have been administered, 31.2 million second doses have been administered, and 18.3 million third doses have been administered.

Tam attributes Canada’s rather low booster shot rate to the fact that some Canadians might have felt a third shot was unnecessary after the latest dip in cases. She also noted that the National Advisory Committee on Immunization still advises those who test positive for COVID-19 to wait three months before getting the jab.

“So I think some of those factors may be playing into why we are not getting the level of boost that we're seeing. I also recognize that at the time of the initial effort in doing the boost campaign, it was in a very difficult period of time when vaccinators were getting infected. We had absenteeism from the public health and health system,†Tam said.