When can we stop wearing masks?

South of the border, Americans got a new directive from their president last week.

"Starting today, if you're fully vaccinated, and you're outdoors and not in a big crowd, you no longer need to wear a mask," President Joe Biden said on April 27.

While it still recommendsmasks indoors, the U.S. Centers for Disease Control and Prevention (CDC) nowsays fully vaccinated Americans can ditch masks when dining outdoors with friends from multiple households and even while attending small outdoor gatherings with vaccinated and unvaccinated people.

More than half of U.S. adults have had at least one dose of aCOVID-19 vaccine, and about 40 per centwere fully vaccinated as of Monday, according to the CDC.

With Canada's vaccination campaign ramping up, especially this month with millions of doses set to arrive, people are wondering when isit our turn to loosen up on masks?

"The discussion about masks is going to depend on the level of vaccinations,"said Doug Manuel, a senior scientist with The Ottawa Hospitalwho does modelling of local COVID-19 numbers.

WATCH | Lower case numbers likely in the fall, scientist says:

When can I stop wearing a mask? Not until case numbers come down, epidemiologist says

3 years ago

Duration 0:55

Doug Manuel, senior scientist at The Ottawa Hospital, says the level of COVID-19 transmission in the community will have to be much lower before the masks come off and those low case numbers likely wont happen until the fall.

"The key to no masks is a low likelihood of transmission in the community, and the key to that will be the level of vaccination."

Herd immunity could be reached, he says, if around 70 to 80 per cent of people are vaccinated, at which point public health restrictions can be relaxed. "We could wear masks below that and still have lowerlevels of transmission," he said.

"As we get good control, then we'll start potentially taking down [restrictions] and making decisions do we want to get back in restaurants before we take off masks?"

About a third of Canadians had received at least one dose of vaccine by Monday. The models for Ontario suggestvaccinationswon't bring down the case numbers until late August and September "under good scenarios," said Manuel.

"In Ottawa, it could be a bit earlier," he said, thoughOttawa city council recentlyextended its mandatory mask ruleforindoor public areas until Aug. 26.

Normal in Asia

Wearing masks in public has been normal for decades in countries like South Korea and China, according toTina Park, a fellow at Carleton University's Norman Paterson School of International Affairs who specializes in the two Koreas and Canadian foreign policy.

"It's been in place long before COVID-19 broke out," said Park.

She says South Korea's experience with Middle East Respiratory Syndrome and fine dust that blows in seasonally from Mongolia and China have contributed to greater public mask use.

"It's seen as acivic duty to make sure you do your part in promoting public health regardless of what your personal feelings may be."

She says she believes trends are pointing to masks becoming normalized in Canada, at least for some time.

"For those who are at risk, for those who feel more comfortable wearing masks than not, I think they will opt to wear masks [out of] fearuntil COVID is no longer a thing," she said.

Canada's Chief Medical Officer of HealthDr. Theresa Tamsaid recentlythe most restrictivepublic health measures like business closures could be gradually lifted this summer as more people receive their first dose of a vaccine.But Tam has also said vaccines won't bethe end of masks.

"These models give us hope, illustrating that there is a safe way to lift most restrictive public health measures," she said on April 23.

Ontario's Ministry of Health did not directly answer CBC News'squestions, but referred to a recent quote from Chief Medical Officer of Health Dr. David Williams, who at a news conference last week noted the population is not yet even 40 per cent vaccinated.

"Once we get to a certain level, we'll be communicating accordingly," said Williams.

Ottawa Public Health says it will follow provincial and federal guidance on masks.

What questions are on your mind as vaccination campaigns pick up across Canada? CBC Ottawa is answering one a day this week.

Monday:When can we start travelling overseas again?