A new study backed by the Centers for Disease Control (CDC) found that a combination of surgical and cloth masks, worn properly, can cut the risk of COVID-19 transmission between two persons as much as 95 percent.
Mask wearing was determined to be an effective deterrent to COVID transmission in mid-2020, but that only works if the mask is worn tightly enough around the nose and chin to prevent errant air from entering around the mask (if your glasses fog up or you feel cool air entering beside your nose, you are probably not wearing your mask tightly enough, say experts).
But new analysis of mask combinations found two options that work well:
- Double masking, or wearing a cloth mask atop a disposable surgical mask
- Or knotting-and-tucking the ear loops on a single surgical mask
From the CDC study:
Results from the first experiment demonstrated that the unknotted medical procedure mask alone blocked 56.1% of the particles from a simulated cough, and the cloth mask alone blocked 51.4%.
The combination of the cloth mask covering the medical procedure mask (double mask) blocked 85.4%of the cough particles and the knotted and tucked medical procedure mask blocked 77.0%.
CDC.gov: Maximizing Fit for Cloth and Medical Procedure Masks to Improve Performance and Reduce SARS-CoV-2 Transmission and Exposure, 2021, Weekly / February 19, 2021
Equally important, the study found that when two people double mask, transmission risks were lowered by 95 percent for both persons. The CDC also recommends other options, including a nylon covering over an underlying mask, if you do not have options for double masking with a surgical mask.

So how do you “knot and tuck”? Here you go:
