Variants of the novel coronavirus are spreading around the world, including the more transmissible one from the UK that has been detected across the US, Europe, and pretty much everywhere in the world. This triggered a discussion among health experts over the quality of face masks, with some, including White House advisor Anthony Fauci, suggesting the use of two masks at once as an extra layer of protection.

There are no specific studies yet on how well face masks work against new variants of the virus — we’re not even sure exactly what makes the new variant more transmissible. But as researchers are trying to unravel these questions, Fauci says that wearing two face masks at once “likely” provides more protection than just wearing one. This hasn’t been recommended yet by the Centers for Disease Control (CDC) at this point.

A mask “is a physical covering to prevent droplets,” Fauci told NBC’s TODAY show. “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. That’s the reason why you see people either double masking or doing a version of an N95.”

The practice suggested by Fauci generated buzz when people were seen wearing two masks at president Joe Biden’s inauguration Wednesday. Pete Buttigieg, who is Biden’s nominee to run the Transportation Department, and poet Amanda Gorman, were seen wearing surgical masks underneath cloth masks, among others.

It’s been an unforgettable and historic day. Congratulations to @POTUS and @VP! https://t.co/xrjIHkeNIt

— Pete Buttigieg (@PeteButtigieg) January 20, 2021

Doing so actually provides larger protection, according to a commentary on mask-wearing published earlier this month. The surgical mask acts as a filter and the cloth adds an extra layer and helps with fit. Wearing two masks would especially help in places where it’s difficult to keep social distance, such as a store.

Other experts agreed with Fauci. “The more layers you have covering your nose and mouth means less virus you’re able to disseminate into the population. And then the more layers you have between you and the environment, the fewer viral particles are going to get into your system,” Thomas Duszynski, head of epidemiology education at Indiana University, told Huffington Post.

Previous studies from last year showed multilayer cloth masks can block up to 50%-70% of fine droplets and particles and limit the spread of the virus. The CDC has so far recommended people to wear masks with 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, have been reported to be more effective at filtering particles than most cloth masks. Meanwhile, N95 respirators, designed to fit close to the face, filters 95% of airborne particles. But they aren’t recommended for the general public and should be reserved for health workers.

The key is to strike a balance between comfort and effectiveness, scientists argue. “If you put three or four masks on, it’s going to filter better because it’s more layers of cloth,” Dr. Scott Segal, chair of anesthesiology at Wake Forest Baptist Health in Winston-Salem, North Carolina, told NBC. “But you’ll be taking it off because it’s uncomfortable.”

Fauci’s suggestion comes at a time of changes in the US regarding the face mask policy. As soon as he took office, President Biden signed a set of executive orders that orders to wear masks on federal property, as well as on airplanes, trains, buses, and airports. “Masks have become a partisan issue, unfortunately, but it’s a patriotic act,” Biden said.

Acceptance of face coverings has come a long way over the past year, as US citizens increasingly use them. A survey in December by the Kaiser Family Foundation showed more than 70% of those surveyed report wearing masks every time they leave their home. This is 21 percentage points higher than a similar survey done in May.