Why are people from out of town able to get vaccinated in San Francisco? FacebookTwitterEmail Friday at the mass vaccination center at City College.Nick Otto/Special to The Chronicle As Bay Area counties race to vaccinate health care workers and elderly residents, some are questioning why out-of-town residents are allowed to get shots at San Francisco’s only mass vaccination site, which opened Friday. It is the latest gripe in San Francisco’s vaccine rollout, which has confused and frustrated many eligible residents who haven’t gotten their shots yet. But city officials say that they have little choice over the matter, as regional health care providers that operate in San Francisco — which receive two-thirds of the city’s entire supply from the state — care for patients from all over Northern California.