Officials were hoping to vaccinate about 3,500 people at the Auto Club Speedway in Fontana where the mass vaccination site was set up.
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Frontline healthcare workers received the vaccine, but the majority of the those who came for vaccinations were residents over the age of 65.
An appointment is required to receive a vaccination. Appointments for Tuesday's event filled up within 17 minutes on Sunday, officials said.
Counties have been under pressure to get as many residents vaccinated as possible. San Bernardino County has been receiving about 16,000 doses of the COVID-19 vaccine each week.
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Until recently, San Bernardino County was saving some of the doses for the second shot.
A county spokesperson said the state has advised that all vaccine doses be used and encouraged the county to try to use them within four days. Because of the logistical challenge, large supersites are important.
"You want something with a huge parking lot where you can set up a lot of cones, that already has streets around it designed to handle a lot of vehicles. You want this to be as easy an experience as possible for the people who are coming here to get vaccinated," said David Wert, a spokesperson for San Bernardino County.
San Bernardino County receives its vaccine shipments every Tuesday and will not know exactly how many doses are available until they arrive.
Officials plan to have another vaccination supersite set up at the Ontario Convention Center on Thursday. All of the appointments for the event were already taken.
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