Are two masks better than one?

KN95 masks are shown for sale in a vending machine at the airport during the outbreak of the coronavirus disease (COVID-19) in San Diego, US. [Reuters]

When it comes to protecting yourself against new coronavirus variants, two masks may be better than one.

A number of politicians, including Vice President Kamala Harris and Senator Mitt Romney, have been spotted doubling up on face masks, and top infectious disease expert Anthony Fauci has recommended that everyday Americans do the same.

As part of our #AskReuters Twitter chat series, Reuters gathered a group of health experts to answer questions about the coronavirus, including what they consider the “right” way to wear face coverings.

Doctors, as well as public health professionals, said any protection is better than none.

“The right kind of mask is one that is worn consistently over the nose and mouth whenever you are in a public space,” said Dr. Matt Binnicker, president of the Pan American Society for Clinical Virology. “At this point, we should focus more on achieving that goal than worrying about double-masking.”

If you do opt to layer your masks, here are some tips to consider.

RISK ENVIRONMENT

The type and number of masks you need will depend on where you are going, according to Dr. Josh Schiffer, professor at Fred Hutchinson Cancer Research Center.

“It is most critical to mask effectively and consistently when in the highest-risk environments for super spreader events,” he said.

Schiffer recommends wearing a cloth mask when walking the dog, for example, and upgrading to a KN95, N95 or double mask when going to the office, grocery store or clinic.

MATERIAL

“If properly worn, all masks are effective,” said Lawrence Gostin, director of the O’Neill Institute for National and Global Health Law at Georgetown University. But the material and fit of a mask can make a bigger difference than the number you wear.

“Double masking is vague because we don’t know what kind of material or fitting,” Gostin said, noting that surgical masks and KN95s perform better.

The experts agreed that an effective face mask should have multiple layers. “At this time, the CDC recommends wearing one face mask with two to three layers,” said Dr. Raed Dweik, chair of Cleveland Clinic’s Respiratory Institute. “If your mask already has multiple layers, it is not necessary to double mask.”

MASK ORDER

When double masking, Dr. Charles Holmes, director of the Center for Innovation in Global Health at Georgetown University, recommends wearing the most effective one on the inside. For example, you should wear a surgical mask over a KN95 mask, or a cloth mask over a surgical mask.

However, Holmes’ biggest piece of advice is simply to cover your face, no matter what that looks like.

“The best mask is a mask you wear consistently and properly,” he said.