Choosing to mask in crowded public places will help curb a triple viral threat

With COVID-19, influenza (the flu) and RSV (respiratory syncytial virus) cases going up during and after the holidays across the country, experts from CoVaRR-Net want to remind you that masking and other preventative health measures have been proven to work. In Ottawa, for example, wastewater testing conducted by CoVaRR-Net’s Wastewater Surveillance Research Group showed that SARS-CoV-2 levels increased by 2.5 times and influenza A levels increased by 1.7 times over the holidays, compared to the previous week, and RSV levels remained high.

The extent to which this trend leads to a surge in respiratory illnesses through January or not will largely depend on whether people take precautions such as staying home if unwell, use of masks, and immunization rates. “When there is a bad respiratory disease season, choosing to wear a mask in crowded places will help to curb widespread transmission of these illnesses, minimize the disruption in schools and workplaces, and take pressure off the healthcare system,” says Dr. Cory Neudorf, Co-Lead of CoVaRR-Net’s Public Health, Health Systems and Social Policy Impacts Pillar, a Professor at the University of Saskatchewan and Interim Senior Medical Health Officer with the Saskatchewan Health Authority.

“We’re talking about people choosing to wear masks for a few weeks in certain settings where transmission risks are high — but not having to wear them for months in most settings,” adds Dr. Neudorf.

Wearing masks in school cuts COVID cases substantially

A major study, published in the New England Journal of Medicine in November 2022, compared COVID-19 cases in Boston-area school districts that ended universal masking policies in February 2022 with cases in school districts that sustained universal masking policies. During a 15-week period there were an additional 44.9 cases per 1,000 students and staff – representing an additional 11,901 cases – in school districts that lifted masking requirements. Approximately 40% of staff cases and 32% of student cases in those districts were associated with removing those policies, resulting in staff and students missing the equivalent of at least an extra 24,000 school days.

“We’ve seen increasing evidence that masks work in different real-world-settings. This well-designed NEJM study is another strong piece of evidence that shows the effectiveness of masks in decreasing respiratory illness spread not just in healthcare settings but in community settings. We also saw how masks, social distancing and lockdowns reduced spread of the flu these past two winters. In the 2020-2021 flu season, for example, only 69 influenza viruses were detected in Canada, compared with an historical average of over 50,000 influenza viruses detected within a season,” says Dr. Cheryl Camillo, Deputy, CoVaRR-Net’s Public Health, Health Systems and Social Policy Impacts Pillar, and Assistant Professor in the Johnson Shoyama Graduate School of Public Policy at the University of Regina.

When is it most important to wear a mask?

Wearing a high-quality, well-fitted mask continues to be one of the most effective tools to protect you from getting COVID-19 and spreading it to others. While mask mandates were necessary early in the pandemic when there were no vaccines, these restrictive measures were never intended to be permanent, explains Dr. Doug Manuel, CoVaRR-Net Public Health, Health Systems and Social Policy Impacts Pillar Deputy, Director of CoVaRR-Net’s Wastewater Surveillance Research Group, and Distinguished University Professor at the University of Ottawa.

“Today, it’s not a matter of people wearing a mask all the time, but a question of when,” says Dr. Manuel. “In January, when the risk of transmitting SARS-CoV-2 could be more than 10 times higher than in July, it’s much more important to wear a mask in confined spaces, crowded places, and close-contact settings. People need to think about the level of risk to themselves and to other people they could be infecting when they make decisions about wearing a mask – and the level of COVID-19 and other respiratory illnesses where they live. Let’s think about protecting vulnerable people and our healthcare system by blunting infection peaks.”

Normalize masks like bicycle helmets and seat belts

Social norms for taking preventive precautions to reduce serious health risks do change over time. It’s become socially accepted and commonplace for Canadians to wear ski helmets, bicycle helmets, and seat belts to reduce the risks of serious injury, and not drink and drive to lower injury risks for themselves and others. Our attitude towards infecting vulnerable people with respiratory illnesses is also changing.

“COVID-19 is a new health risk, on top of existing seasonal respiratory infections that have been a major health burden. We need to discuss our social norms about respiratory illness and prevention,” suggests Dr. Manuel. “Do your risk assessment ahead of time, so you can develop an effective prevention plan. It’s similar to our social norms for drinking and driving. Before attending a party, people think ahead about who the designated driver will be or whether to take a taxi. If you’re going to a crowded concert or movie theatre in January and seeing your elderly parents or grandparents the next day, take the precaution of wearing a mask since the risks of viral infection are high.”

Consider wearing a mask if you are:

• living in a community with high levels of COVID-19 or other respiratory illnesses
• in crowded public places including schools, malls, retail and grocery stores, public transportation, airplanes, arenas and theatres
• in poorly ventilated workplaces or other settings
• at higher risk of severe disease or outcomes
• infected or sick with COVID-19 or another respiratory illness
• in contact with others at risk of severe disease or outcomes and in healthcare settings
• visiting a group-living situation

Keep schools, workplaces, and hospitals productive

Choosing to wear a mask in high-risk situations will have a ripple effect in terms of the benefits to the Canadian economy and society. “If people take the appropriate masking precautions when the risks of respiratory illness are high, this leads to far less viral illness in the community. This has a huge positive impact on workplace productivity and continuity in school attendance, while also reducing strain on the healthcare system and serious health complications in the population,” says Dr. Camillo.

To arrange an interview with Cheryl Camillo, Doug Manuel, or Cory Neudorf, please contact:
media@covarrnet.ca