With cases of COVID-19 rising locally and increased circulation of the highly transmissible Delta variant, the Counties of Alameda, Contra Costa, Marin, San Francisco, San Mateo, Santa Clara, Sonoma, and the City of Berkeley recommend that everyone, regardless of vaccination status, wear masks indoors in public places as an extra precautionary measure for those who are fully vaccinated, and to ensure easy verification that all unvaccinated people are masked in those settings.
More information can be found at:
https://cchealth.org/press-releases/2021/0716-Masking-Indoors-for-Everyone.php