Anyone hoping to be vaccinated at one of the COVID-19 mass-vaccination centers in Santa Clara or San Mateo counties is likely to be turned away if they have a primary care physician, according to Santa Clara County staff. The county's website, sccfreevax.org, provides updated information about who is eligible for the vaccine, where it is available and how to make appointments. "Healthcare systems throughout the county are rapidly scaling their capacity to administer vaccines to the public, but this expansion is dependent on the supply of available vaccines. The County will continue to provide the public with regular updates regarding the availability and distribution of COVID-19 vaccines," county officials said.