The delta variant is driving up coronavirus cases in California, landing the Bay Area on a federal “hot spot” watch list and spurring renewed urgency to get shots into the arms of people who haven’t been vaccinated, even in areas where immunization rates are already high. In San Francisco, public health officials are now requiring all workers at hospitals, nursing homes, jails and shelters to be vaccinated by Sept. 15. That’s a shift from an earlier order that mandated vaccination only after at least one vaccine was fully approved by the Food and Drug Administration, which now allows the shots...