Why snug fitting, multi-layered masks are the most effective

COVID-19 spreads when an infected person breathes out droplets and very small particles that contain the virus. These droplets and particles can be breathed in by other people or land on their eyes, noses, or mouth. The Delta variant is about two times as contagious as the original strain.

The best protection we have against getting COVID-19 is to get vaccinated. For added protection, we should wear masks indoors and in crowded outdoor settings to shield ourselves and those around us.

Masks are part of a layered approach that greatly reduces the spread of COVID-19. Masks combined with vaccinations, social distancing and frequent hand washing contribute to a winning strategy to end this pandemic.

The CDC estimates more than 50 percent of COVID-19 transmission occurs from people who are asymptomatic or presymptomatic and are not aware they are infected. This underscores the importance of mask wearing for everyone.

The basics of how masks work

Everyone has probably seen someone wearing a mask below their nose. Most of us know it needs to cover our nose and mouth to offer protection.

How does a mask work and what can we do to make the mask we wear more effective?

Simply put, when you breathe through a mask, it creates a barrier against large respiratory droplets getting in or out and a good filter for smaller microscopic droplets, all that can contain viruses. Studies show a cloth mask can stop 50 to 80 percent of all droplets from escaping and up to 50 percent from entering. This means masks provide protection to both the wearer and those around them. 

How to help your mask help you

A mask with multiple layers that fits snug is most effective 

Choose a mask that fits snugly against the face and is secure under the chin. A mask that has gaps around the nose or on the sides along the cheeks allows air to freely leave or enter. Masks with nose wires can improve the fit and ensure most air is being filtered through the mask. 

A cloth mask with multiple layers of washable, breathable, tightly woven fabric blocks more droplets than a cloth mask with only one layer of fabric. A study by the University of Illinois found the first layer reduces the speed of the droplets that escape allowing the second layer to trap and block most of the remaining droplets, as much as 94 percent total. 

Some masks have space for an additional layer of fabric to be inserted. A cloth mask may be worn over a disposable mask. Do not wear two disposable masks or masks with ventilation valves. Finally, make sure that you pick a mask that is also comfortable wear and breathe through. The most effective mask is the one you will wear.