California follows CDC, advises indoor masks for vaccinated Pexels SACRAMENTO, Calif. (AP) — California’s public health agency is recommending that people wear masks indoors, regardless of vaccination status, as protection against the contagious delta variant. Wednesday’s announcement follows an about-face by the U.S. Centers for Disease Control and Prevention, which recommended Tuesday that fully vaccinated people mask up in public indoor settings in areas where transmission is high or substantial. Riverside, Los Angeles, and San Diego counties are listed as high transmission areas Riverside County's Supervisor Supervisor Karen Spiegel said the county is not planning to issue a mask mandate at this time.