Beginning December 15, 2021, the California Department of Public Health (CDPH) will require masks to be worn in all indoor public settings, irrespective of vaccine status, through January 15, 2022, at which point they will make further recommendations as needed in response to the pandemic.
You can find more information on the requirement here.
Today, the California Department of Public Health(CDPH) released the most recent statistics on COVID-19 and updates on the state's pandemic response. The most up to date data is available on the state's COVID-19 data dashboard.
Cases, hospitalizations, and deaths are largely occurring among unvaccinated populations. See the data for unvaccinated and vaccinated cases, hospitalizations and deaths.