COVID-19 (coronavirus) Featured

Sunnybrook experts answer your questions about double masking and COVID-19 variants

Dr. Samira Mubareka (left) and Natasha Salt

Earlier in March, we asked our followers on Instagram to send us their COVID-related questions about double masking and the new variants. Two Sunnybrook experts have weighed in below: Natasha Salt, director of infection prevention and control, has answered questions on double masking and Dr. Samira Mubareka, microbiologist and infectious diseases physician, has answered questions about the variants. 

When should you double mask?

Natasha Salt (N.S.): Double masking may be considered for non-medical masks, or those used outside healthcare by the public. The main premise, around any mask, in addition to filtration, is that it should fit snuggly around the nose, chin and cheeks in order to be effective. The Public Health Agency of Canada (PHAC) also recommends that non-medical/fabric masks are made of at least 3 layers. When you don’t have tight fitting non-medical mask or triple layer fabric mask, you may consider doubling up to add layers (improving filtration and fit) to your existing mask.

Which types of masks should be doubled, and which are good on their own?

N.S.: Double masking may help improve the fit of some cloth masks and may provide more protection if your mask only has one or two layers. How well a non-medical mask works depends on the materials used, how the mask is made and how well it fits. A well-fitting mask should:

  • Be large enough to completely and comfortably cover your nose, mouth and chin without gaps
  • Fit securely to your head with ties or ear loops
  • Be comfortable and not require frequent adjustments
  • Maintain its shape after washing and drying

Medical-grade, well-fitting masks are fine to wear on their own, and do not need to be layered. If you have a medical-grade mask that is a bit loose, you may consider using “ear savers” or tightening ties to improve seal.

Is it true that I should wear 1 mask instead of 2?

N.S.: If your cloth mask fits properly and has 3 layers, you do not need to double mask. The most important thing is to continue following public health guidelines for preventing COVID transmission – clean your hands, stay home if you are unwell, practice physical distancing, make essential trips only, wear your mask properly and don’t touch your face.

Does double masking make a big difference?

N.S.: If your cloth mask fits snugly around the eyes, nose and chin, and leaves no gaps on the side, double masking may not make a difference. If you want to improve the fit of your cloth mask (and you don’t have underlying breathing problems) double masking may help.

Remember, whether you’re wearing one mask or two, they need to be changed routinely. Discard disposable masks and launder reusable masks at least daily (or more often if you wear them continuously).

The biggest difference we can make is to continue following all recommended public health recommendations, like wearing a mask, cleaning our hands, practicing physical distancing and limiting travel to essential trips only.

I work in a grocery store and have been doubling up on masks. Is that a good idea?

N.S.: Double masking may help you improve the fit of your cloth mask, if that is an issue you’re experiencing. However, wearing two masks may be more uncomfortable, cause you to touch your face more often to make adjustments, which can promote infection by bringing in more germs to your nose and eyes. You may want to consider other options, such as wearing a 3-layer mask (with a filter) and ensuring your mask fits properly.

I have asthma. When I double mask, I feel like I’m suffocating. Could you suggest an alternative?

N.S: Consider buying a 3-layer cloth mask with a filter in it, which provides enough protection to make double masking unnecessary. The mask should be made of a breathable material and should fit your face properly.

If the mask you’re wearing is making it difficult to breathe, that’s a sign that you need to step away from that situation and give yourself a break. Take off that mask in a safe zone where you’re able to do so and take a rest.

Should front-line health-care workers be double masking now?

N.S.: If you are a healthcare worker with access to medical-grade personal protective equipment (PPE), you do not need to double mask at work. Doing so increases your risk of self-contamination by adding additional complexity and increasing discomfort and perspiration, making it more likely that you bring your hands up to your face to adjust your PPE.

If you wear a surgical mask as the inner mask, can you reuse it?

N.S.: If it is a medical-grade surgical mask, you do not need to double mask. Medical masks should be properly disposed of after each use.

Is double masking better than a shield and mask?

N.S.: No. For health care workers, the CDC recommends against wearing two disposable, medical-grade masks at the same time. In situations where health care workers have been wearing multiple medical-grade masks at work, we actually have seen transmission, which we think is from self-contamination.

Do you expect to see more variants in Canada in the coming months?

Dr. Samira Mubareka (S.M.): Yes, that is something we’re preparing for. While our team is studying the original dominant strain, we are sequencing the genomes of the variants as well. It’s likely we will continue to see mutations in new variants that make the virus more adaptable and transmissible. To date, the new variants of COVID-19 that were first detected in the U.K and South Africa have been found in Ontario, but the extent of their spread is not yet fully known. Recent testing has shown that B.1.1.7 variant first detected in the UK is approximately 20% of the virus circulating.

What makes the variants more contagious?

S.M.: Very little is known about the precise mechanism for enhanced transmission for some of these variants – for example, the B.1.1.7 variant has approximately a 30-50% increased risk of transmissibility, meaning a person has higher odds of becoming infected.

Scientists are still studying the variants to understand whether this is related to virus entry into the cell and enhanced replication and related factors like shedding, persistence in air or other aspects of the environment. The ability of variants of concern to evade the immune system and the potential role in transmission are also currently being studied.

Does the vaccine protect against the new variant?

S.M.: There are a lot of unanswered questions when it comes to the variants, and it will take more time before we know how they will impact the vaccine’s efficacy. However, infectious disease specialists are confident the approved vaccines will work on these variants to some extent.

Several new variants that have been identified in the U.K., Brazil and South Africa. So far, it appears the vaccine may not be as protective against the South African (B.1.351) variant, but it is effective against the U.K. (B.1.1.7) variant.

About the author

Sybil Millar

Sybil Millar

Sybil Millar is the Communications Advisor for Infection Prevention and Control, Infectious Diseases, the Ross Tilley Burn Centre and the Critical Care program at Sunnybrook.

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