County of Marin - News Releases - Summer Mask Use

For Immediate Release
July 21, 2022

Masks: The Essential Summer Accessory of 2022

Data shows the highly infectious BA.5 Variant is Dominant Strain in Marin

San Rafael, CA – With Summer activities in full swing, new variant data reinforces the recommendation to wear a high quality, well-fitting mask in indoor public settings to protect against COVID-19 infection.

Since the beginning of July 2022, 90% of COVID-19 samples tested in Marin County were BA.4 or BA.5 variants of Omicron. This follows three months of high transmission rates with BA.2-related variants. The new strains are proving to be even more infectious, and better able to evade the immune response than prior strains.

Marin County Public Health does not intend to institute a local mask mandate. Instead, health authorities are providing information to guide community members’ choices based on the risks they face, recognizing the protection high quality masks provide.

Given current rates of COVID-19 among people tested in Marin hospitals, an estimated 5 percent, or 1 in 20 Marin County residents are currently infected.

“Knowing the risk of exposure to the virus in everyday activities, like going to the grocery store, can help us make informed choices,” said Marin County Health and Human Services epidemiologist Lee Ann Prebil. “We hope sharing these data brings the point home-- these days the odds are high that the virus is in the air in indoor public settings in Marin.”

Estimated likelihood of being exposed to COVID-19 virus in gatherings of various sizes in Marin (July 2022):

Number of people present

Likelihood at least one person is infected









Estimated community prevalence 5%

“If you’re serious about not getting infected, or if someone at home is at risk severe COVID-19, wearing a good mask is the right decision,” said Dr. Matt Willis, Marin County Public Health Officer. “This is how healthcare workers have used masks for decades—before coming into a room with someone who might be sick, pulling on a high-quality mask that blocks the germ entirely. It’s a simple step.”

Upgrading to a N95, KN95 or KF94 mask helps protect the wearer from inhaling the virus and becoming infected. These higher quality masks form a seal around the nose and mouth, filtrating airborne particles that could be inhaled. Cloth masks offer limited protection against highly infectious variants when community case rates are high.

Dr Willis shared a video highlighting the role of masks as we move into the BA.5 era for Marin County.

High quality masks are available for purchase in local at pharmacies, hardware and industrial supply stores, and some grocery and convenience stores. CDC’s Free Mask Locator lists local pharmacies offering free masks. Trusted online retailers also offer easy access to high quality masks. CDC offers tips on how to spot fake N95, KN95, and KF94 masks.

In addition to promoting mask use, as a response to the emergence of the BA.5 variant Marin County Public Health is strengthening the recommendation for all residents age 50 and older to obtain a second booster dose.

Learn more about mask use at


Laine Hendricks
Public Information Officer
County Administrator's Office

3501 Civic Center Drive
Suite #325
San Rafael, CA 94903
(415) 473-7496
Email: Laine Hendricks
County Administrator website