FONTANA (CBSLA) – About 3,500 people were receiving the coronavirus vaccine Tuesday during a one-time vaccination event at the Auto Club Speedway in Fontana.

A COVID-19 vaccine event at the Fontana Auto Club Speedway. Feb. 2, 2021. (CBSLA)

The event was primarily focused on providing vaccinations for seniors 65 and older, although some healthcare workers and frontline workers were also being vaccinated.

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San Bernardino County spokesperson David Wert told CBSLA Monday that all 3,500 appointments were filled up in just 17 minutes when the sign-up window opened up online.

“You just gotta keep trying,” vaccine recipient Fred Berzak told CBSLA. “I’ve been trying for weeks, and finally yesterday I was able to get in.”

Wert said that the county was forced to make this a one-day only event because of the limited supply in doses.

“We have the capacity, the county does, to run these events a lot more often, to open more clinics,” Wert said. “We have the personnel, we have the locations, we just don’t have the vaccines that we need. So one of the things we’re hoping to do here is demonstrate to the state we can vaccinate a lot of people if we get the vaccines.”

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Those who get the vaccine Tuesday will be able to immediately schedule a booster shot for a second event that will take place March 2, also at the Speedway, San Bernardino County said in a news release.

“While we are unable to immediately accommodate everyone who would like to be vaccinated, establishing this large, centrally located site represents an important milestone in our battle against the coronavirus,” San Bernardino Supervisor Curt Hagman said in a statement. “We plan to announce additional vaccination sites throughout the county, including mobile vaccination teams, as soon as the State provides the County with sufficient doses.”

Meanwhile, the Ontario Convention Center will open Thursday as a vaccination super site. It will operate Monday through Friday from 10 a.m. to 6 p.m.

San Bernardino County residents eligible to receive the vaccine can attempt to schedule an appointment here.

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San Bernardino has recorded at least 275,076 coronavirus cases and has 1,856 deaths from the disease since the pandemic began.