If you're concerned that Santa Clara County is the only one in the Bay Area mandating mask-wearing in public indoor spaces during this stage of the COVID-19 pandemic, you can take solace in your own high-quality mask.
That's according to Dr. Peter Chin-Hong, Professor of Medicine and Associate Dean for Regional Campuses at UCSF. Chin-Hong told KCBS Radio's Holly Quan and Jason Brooks on Friday morning that a fully vaccinated or boosted person will be significantly protected indoors if they're wearing a KN95, N95 or KF94 mask – even if few others are.
"With upgrading the masks and not wearing the cloth masks anymore, you do have much more protection, even if nobody else is having a mask on," Chin-Hong said during "Ask An Expert" on Friday in response to a listener question. "And that's why, I think, we feel confident with ... not having the mask mandate because we are not relying on cloth masks anymore."
Before California lifted its statewide public indoor mask mandate last week, officials recommended residents upgrade to a high-quality mask in the early days of the omicron variant's surge. Cloth masks were deemed no longer sufficient enough to prevent transmission of the virus.
Chin-Hong said a surgical mask should provide sufficient protection for a quick visit to an indoor space, such as a grocery store, as the masks offer about an hour of protection. A KN95, which Chin-Hong deemed "the Tesla of masks," can provide hundreds.
Double-masking with a surgical mask and a cloth mask, no matter which is layered on top, will also protect the wearer more than either individual mask would on its own. But N95, KF94 and KN95 masks are at "the top of the heap," Chin-Hong said.
"In general, I kind of use my surgical mask as an all-around mask," Chin-Hong said. "And if you're on a plane or in an environment for a very long time, wearing one of those higher-grade masks will give you more confidence."