Masks have proven effective against COVID-19, but emerging variants raise questions: Is one enough? Double masking is catching on, especially in the US. Does it really enhance protection? Some avoid masks entirely, while others, like US President Joe Biden—who wore two overlapping masks during his campaign—opt for extra layers. Experts are divided.
A CDC study published February 10 showed that wearing two masks or tightly knotting a single surgical mask reduces exposure to infectious aerosols by over 95% in lab tests with mannequins.
John T. Brooks, MD, lead for CDC's COVID-19 response
Source: CDC
"Double masking adds an extra filtration layer, blocking virus-laden droplets more effectively," explains Aline M. Holmes, Clinical Professor at Rutgers University School of Nursing, in Prevention.com.
Video of the day:Scott Segal, PhD, who researched mask fabrics, notes: "Two masks make sense if filtration is suboptimal." He recommends a surgical mask topped with a snug cloth one for optimal fit, per Health magazine.
US experts agree: Pairing masks improves protection if neither fits perfectly alone. "Ensure the inner mask seals well over nose and mouth," advises William Schaffner, MD, infectious disease expert at Vanderbilt University Medical Center.
Comfort matters—if double masking hinders breathing, skip it. "An unwearable mask is useless," Segal cautions, as fidgeting reduces efficacy.
"No solid evidence supports overlapping masks," stated Didier Lepelletier, MD, co-chair of France's High Council for Public Health COVID-19 group, in Le Parisien on January 18. A 2005 study advised against it, favoring certified Category 1 masks.
France's High Council now recommends Category 1 masks over homemade or Category 2 options amid variants, including for schoolchildren.
"It's minimally useful and risks poor handling or self-contamination," says Bruno Grandbastien, MD, president of the French Society of Hospital Hygiene, on BFMTV.
Fabien Squinazi, MD, PhD, agrees: "Double masking isn't necessarily better—it can impede breathing and compliance," he told the same channel.
Beyond masks, sustain hand hygiene, sanitizer use, and distancing to combat COVID-19.
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