The Centers for Disease Control and Prevention (CDC) concluded last week that new ways of wearing face masks dramatically reduce the risk of contracting COVID-19.
The CDC said research findings show two methods of applying masks improve the protection that masks provide.
First, the agency said, users should fit a cloth mask over a medical procedure mask — essentially wearing two masks — to increase protection. Second, the agency said, knotting the ear loops of a medical procedure mask and then tucking in the excess material to flatten the extra material close to the face increases the virus barrier.
Each modification substantially improves the barrier and reduces wearer exposure, the CDC advises.
“These laboratory-based experiments highlight the importance of good fit to optimize mask performance,” the study’s authors wrote.
“Until vaccine-induced population immunity is achieved, universal masking is a highly effective means to slow the spread of SARS-CoV-2 [COVID-19] when combined with other protective measures, such as physical distancing, avoiding crowds and poorly ventilated indoor spaces, and good hand hygiene.”
The authors added that the findings in the report are subject to at least four limitations.
First, these experiments were conducted with one type of medical procedure mask and one type of cloth mask among the many choices that are commercially available and were intended to provide data about their relative performance in a controlled setting.
Second, these experiments did not include any other combinations of masks, such as cloth over cloth, medical procedure mask over medical procedure mask, or medical procedure mask over cloth.
Third, these findings might not be applicable to children because of their smaller size or to men with beards and other facial hair, which interfere with fit.
Finally, although use of double masking or knotting and tucking are two of many options that can optimize fit and enhance mask performance for source control and for wearer protection, double masking might impede breathing or obstruct peripheral vision for some wearers, and knotting and tucking can change the shape of the mask such that it no longer covers fully both the nose and the mouth of persons with larger faces.
Universal masking is one of the prevention strategies recommended by the CDC to slow the spread of COVID-19 since the onslaught of the pandemic last March.
As of Feb. 1, 38 states and the District have universal mask mandates. Mask wearing has also been mandated by executive order for federal property as well as for domestic and international travel.
Face masks substantially reduce exhaled respiratory droplets and aerosols from infected wearers and reduce exposure of uninfected wearers to these particles says the CDC.
“Controlling SARS-CoV-2 transmission is critical not only to reduce the widespread effects of the COVID-19 pandemic on human health and the economy but also to slow viral evolution and the emergence of variants that could alter transmission dynamics or affect the usefulness of diagnostics, therapeutics, and vaccines.”