Which masks work best against Omicron? Experts are divided, but most say ditch cloth masks – National

Canadians are urged to ditch certain types of masks in favor of those that experts believe will offer more protection against the new, rapidly spreading Omicron variant.

The head of the Ontario Science Advisory Table, Dr Peter Juni, said on Friday that single-layer fabric face masks may not be enough to protect against Omicron.

“The problem here is that if you have a single layer, the filtration capacity is absolutely minimal and doesn’t make any difference,” said Juni, who pointed out using KN95 respirators as a more effective option.

The renewed discussion over mask use comes as Canada’s Omicron-led fifth wave continues to push the number of daily cases to a record high not seen in months, pushing provinces to adopt a host of health and safety measures and restrictions. public health.

Juni’s recommendation to ditch single-layer fabric face masks comes amid a call from some public health experts to reconsider masking guidelines and more actively encourage the use of respirators and medical masks over those Fabric.

Colin Furness, an epidemiologist at the University of Toronto, said public health authorities need to more strongly encourage the use of KN95 respirators in indoor public places.

Furness told The Canadian Press that any campaign to promote their use should include resources to help Canadians find the most suitable respirators.

“This is the public education that we desperately need,” Furness said. “The fact that people are alone for this is a travesty. “

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In November, the Public Health Agency of Canada (PHAC) updated its guidelines for mask use, suggesting that respirators such as the KN95 are more effective than non-medical masks.

“In general, while non-medical masks can help prevent the spread of COVID-19, medical masks and respirators provide better protection,” PHAC said on its mask information webpage.

The agency also recommended the use of medical masks or respirators for people in vulnerable risk groups or who are at higher risk of contracting COVID-19 in the course of their work or life.

At a press conference on Friday, Canada’s Chief Public Health Officer, Dr. Theresa Tam, also insisted that Canadians follow PHAC’s updated guidelines on indoor ventilation and “l ‘proper use, construction and fit of face masks’.

While respirators appear to be the subject of a consensus among experts and public health officials as the gold standard for protection against Omicron, they are quick to point out that the additional protection offered by respirators depends on a lot of the fact that the masks fit properly to a person’s face.

This is a detail that Dr. Gerald Evans, Director of Infectious Diseases at Queen’s University, was quick to point out.

“The amount of extra protection you get from an N95 respirator… if not tested, is only slightly better than a medical mask,” Evans said.

While there is a benefit to the protection offered by respirators if they are properly fitted, Evans also pointed out the high cost of acquiring them regularly, as well as the lack of definitive evidence that N95s prevent transmission in environments. community, more than less expensive. produces medical masks.

“So there is no study that shows that wearing an N95 statistically or clinically reduces the transmission of COVID 19 – more than a medical mask,” Evans said. “In fact, we have very good evidence that medical masks clearly work by reducing the overall infectious dose. “

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In conflicting guidelines on what appears to be the use of masks by the general public, PHAC said that a “respirator worn in the community does not need to have been formally tested as required in some professional circles ”.

Evans also said that Omicron’s increased transmission is not due to being “more airborne” – a virus trait that a ventilator could further protect users from. On the contrary, he said, people with the variant start shedding higher loads of the virus, due to its rapid replication in the cells it infects.

The gist of Evans though is, “If you’ve got a lot of money and can afford an N95 mask or one of those equivalents, go ahead and buy them.”

“But if you can get yourself a medical mask – they’re not very expensive… and if you can’t afford it, but you have good sheet masks, use them, don’t forget to bring them. clean up and probably think about double masking if you think it’s appropriate.

– With files from The Canadian Press