N95s, double-masking offer more protection as omicron spreads, study shows

Posted at 12:12 PM, Dec 21, 2021

SAN DIEGO — The omicron variant is spreading quickly around the country, and health experts believe another surge in COVID-19 cases is on its way.

As has been the case for the last year-and-a-half, experts say the best way people can protect themselves is to wear a mask indoors or in a crowded space. But which face coverings provide the most protection against COVID-19?

A University of Minnesota study looked at how long it takes a person to be infected by COVID-19 according to the type of mask they were wearing around an infected person.

For example, if an infected person is maskless and an uninfected person is wearing a cloth mask, the study found it took the person wearing a mask 20 minutes to get infected.

The timespan increased to 30 minutes for those wearing a surgical mask and two-and-a-half hours for those wearing a fit-tested N95 mask or a similar model, like a KF94 or KN95.

Protection time increased further if the infected person was also masked.

The study suggested that an infected person could share the same space with an uninfected person for 25 hours without passing on the virus if both wore a fit-tested N95.

"If you're going to be in an indoor place for a while with other people, then upping the game to a KN90 or an N95 is really the way to go," said Dr. Christian Ramers, an infectious disease specialist at the Family of Centers of San Diego.

Ramers said that the caveat of the study is that it did not account for new variants.

"Now that we have omicron, which is two to five times more infectious than delta, we would take those numbers of protection and reduce them even further," Ramers said.

Unlike last winter, there currently is not a significant PPE shortage. Americans now have access to higher-grade masks, even though they are intended for hospital settings.

However, Ramers says double-masking will work in a pinch for those who don't have access to N95s or KN90s.

"If you can't get your hands on a higher quality mask, then using a cloth and then a surgical is the way to go," Ramers said.

He said double-masking will be less comfortable but will offer significantly more protection.

Ramers says he's seen about 30 severely ill COVID-19 patients a week for the last two years at his monoclonal anti-body infusion clinic. Every day he wears a fitted N95 mask and has never tested positive. He is also fully vaccinated.

This story was originally published by Rina Nakano on Scripps station KGTV in San Diego.