Could wearing two face masks at once during the pandemic provide more protection than just wearing one? According to White House advisor Dr. Anthony Fauci, “it likely does,” he told NBC News’ TODAY on Monday.

As Fauci explained, masks are physical coverings that prevent respiratory droplets from spreading to other people and provide a degree of protection to the wearer.

“So if you have a physical covering with one layer, you put another layer on, it just makes common sense that it likely would be more effective,” Fauci told TODAY. “That’s the reason why you see people either double masking or doing a version of an N95.”

Although the Centers for Disease Control has not recommended double masking yet, the practice generated buzz when people were seen wearing two masks at president Joe Biden’s inauguration Wednesday. Viewers noted that poet Amanda Gorman and Pete Buttigieg, who is Biden’s nominee to run the Transportation Department, wore surgical masks underneath cloth masks.

Researchers say that wearing a surgical mask underneath a cloth mask provides maximal protection, because the surgical mask acts as a filter and the cloth adds an additional layer and helps with fit, according to commentary on mask-wearing published on Jan. 15. In places where it’s difficult to maintain social distance, such as on an airplane or at the store, two masks would provide additional protection. The next best option would be a three-layer mask that contains an inner filter.

Studies have shown that multilayer cloth masks can both block up to 50%-70% of fine droplets and particles and limit the spread of Covid. The CDC recommends that people wear masks that have at least two layers of tightly woven cotton fabric, such as quilting fabric or cotton sheets.

Disposable surgical masks made from a plastic-derived material called polypropylene have been shown to be more effective at filtering particles than just a cloth mask.

N95 respirators are face masks that are designed to fit very close to the face, forming a seal that filters 95% of airborne particles. These masks are not recommended for the general public, because they should be reserved for healthcare workers and medical first responders.

President Biden signed executive orders on Thursday that mandate wearing masks on airplanes, trains, buses, airports as well as on federal property.

A December survey from the Kaiser Family Foundation found that more than 70% of Americans report wearing masks.