The U.S. Centers for Disease Control and Prevention recommended on Wednesday that Americans wear two face masks as a strategy to help protect them from the novel coronavirus.
In a report released Wednesday morning, officials said people who wore cloth masks over medical procedure masks were able to block 92.5% of particles released from a simulated cough. A single medical procedure mask on its own blocked only 42% of particles.
Researchers determined that double-masking around people who are coughing while unmasked protects against 83% of particles, and wearing a single mask with the ear loops knotted, tucked in and flattened protects against nearly 66% of particles. The best protection was seen when both parties wore fitted masks, officials said, either through double-masking, which blocked 96.4% of particles, or through knotting and tucking their masks, which blocked nearly 96% of particles.
“Masks substantially reduce exhaled respiratory droplets and aerosols from infected wearers and reduce exposure of uninfected wearers to these particles,” officials said in the report. “The effectiveness of cloth and medical procedure masks can be improved by ensuring that they are well fitted to the contours of the face to prevent leakage of air around the masks’ edges.”
At a news conference on Wednesday morning, CDC Director Dr. Rochelle Walensky said several different strategies had been identified to improve mask fit.
“This includes wearing a mask with a moldable nose wire, knotting the ear loops on your mask or wearing a cloth mask over a procedure or disposable mask,” she said.
The report came after officials conducted experiments last month in laboratory settings to compare the efficacy of double-masking, single-masking and wearing a single mask with knotted ear loops.
As of Wednesday afternoon, the U.S. continues to lead the world with 27.2 million COVID-19 cases. The viral infection has caused more than 468,000 deaths nationwide, according to a tally from Johns Hopkins University.
Globally, 107 million people have been diagnosed with COVID-19, resulting in 2.3 million deaths.