Spread of more infectious coronavirus variants in Canada requires renewed vigilance, experts say
The spread of more contagious coronavirus variants in Canada amid already high levels of COVID-19 makes it a critical time to think about the masks we wear.
Whether that means finding better quality masks, doubling up on masks, or wearing them in settings we wouldn’t normally think to, experts say it’s time we step up our game.
The variants first identified in South Africa and the U.K are spreading in Canada, in some cases with no known link to travel, and have already led to devastating outbreaks in long-term care homes.
The variant discovered in the U.K., known as B117, is estimated to be at least 56 per cent more transmissible and potentially more deadly than the original coronavirus strain.
But even as COVID-19 case numbers show early signs of slowing down in Canada, experts say it’s becoming more important than ever to lower our risk of exposure as much as possible to prevent variants from taking hold here.
“The floodwaters are receding right now, but it’s still very, very dangerous,” said Erin Bromage, a biology professor and immunologist at the University of Massachusetts, Dartmouth who studies infectious diseases.
“If [B117] does pop up as the dominant variant here, we are going to need to really up our game in regards to masks, in regards to … how many contacts we have in a day, because it definitely appears to have an upper hand.”
‘Time to step it up’ with masks
Canada currently recommends the use of three-layer non-medical masks with a filter layer to prevent the spread of the virus, but has not updated its recommendations since November, before the emergence of new variants.
Dr. Zain Chagla, an infectious diseases physician at St. Joseph’s Healthcare Hamilton, said that while three-layer non-medical masks are a good “minimum standard,” Canadians should opt for masks that offer better protection whenever possible.
Those include surgical masks, which are a step below N95s and KN95s and come in three different filtration levels determined by the American Society for Testing and Materials (ASTM).
“When I go to the grocery store now, I wear my very best mask,” said Linsey Marr, one of the top aerosol scientists in the world and an expert on the airborne transmission of viruses at Virginia Tech. “Before I was wearing an OK mask that was comfortable and easy.”
She said a cloth mask can “easily filter out half of particles, maybe more, but we’re at the point where we need better performance.”
Bromage said he changed his approach to masks several months ago when COVID-19 cases started to spike in many parts of North America. That’s when he ditched common cloth masks for surgical masks, he said.
Bromage said Level 3 ASTM surgical masks, those that are used at dental clinics, for example, offer both a better level of protection and a better quality fit.
“The most important part is you’ve got to make sure your breath actually goes through the material,” he said.
“You really should see the mask expand and then collapse and expand and collapse with each breath that you take. That’s a good indication that what you’re breathing is actually going through the material.”
Outdoors not without risk
Coronavirus variants can also change the level of risk we face in situations that are typically more safe, such as being outdoors.
Places such as San Francisco and New Brunswick have mandated outdoor mask use, and Toronto recently announced it now requires face masks for outdoor activities such as skating.
“The risk is much lower outdoors than indoors, but with the new variants, we should be more careful outdoors as well as indoors,” said Marr.
“The times we need to be paying attention to it is if there are a lot of people around at a sporting event, or in a crowded park, or if you’re out walking or running and you’re passing by several people per minute, because all those little exposures can add up over time.”
Bromage said he wears a cloth mask or surgical mask with a lesser filtration level when in an isolated area outdoors, but gets concerned when he sees a group of people huddling together outdoors without moving around.
“The closer you are outdoors, the much more risky it is,” he said.
While not common, there have been cases of outdoor transmission of COVID-19 in Canada.
Canada is on the hunt for coronavirus variants — but may not be able to keep up with outbreaks
“Again it comes down to being in close contact, without a mask, talking loudly or sharing food and drinks that makes it risky even outside,” Henry said.
She said B.C. has not seen transmission from brief outdoor encounters, waiting in line outside or at outdoor picnics where people maintain a reasonable distance and wear masks when close for short periods of time.
Chagla said standing six-feet apart while wearing masks is a responsible way to interact with others outdoors.
“There are ways to do things outdoors safely, even in the context of the variant,” said Chagla. “You don’t want outside to be a free pass, but you also want to use it for what it is, to let people see each other and have contact with humanity, too.”
Bromage said that while the risk of exposure outdoors is less than indoors, the risk of both is higher due to the emergence of coronavirus variants.
“It’s really time that people think about upping their game just in general,” he said.
“Because if we are going to get a new wave from this variant, and it’s already going to build off a very high level of infection that we already have, we need to do better to keep it out of our lives.”