Appointments quickly filled up Monday morning for San Bernardino County’s COVID-19 vaccine “super site event” at the Auto Club Speedway in Fontana, officials said.

Residents 65 and older, health care workers and emergency service professionals who live or work in the county were told they could sign up online to get their shots beginning at 9 a.m. at sbcovid19.com/vaccine.

All 3,500 available appointment slots were booked in less than 20 minutes, county Supervisor Janice Rutherford told KTLA.

“We’ve got millions of residents who want to get into this site. It’s gonna be slow, it’s going to be a little bit of a challenge,” Rutherford said. “We ask you to be patient and we ask you to check back because we’re gonna have more mass vaccination sites, this is just our first one.”

Vaccinations are set to begin at the Auto Club Speedway, 9300 Cherry Avenue, on Tuesday.

Anyone who gets their shot at the speedway will be able to immediately schedule an appointment to get their second dose at a follow-up event on March 2, according to a county news release.

“Those who secure a Tuesday appointment should expect to be onsite for approximately one hour, and are being asked to arrive no earlier than 15 minutes prior to their scheduled time,” county officials said.

Residents were told that booking appointments through the website “will provide the best chance for securing a spot,” and those who don’t know how to sign up online were encouraged to ask friends and family for help, according to a county news release.

“As the state gets us more vaccines, we’ll continue to have more mass vaccination sites at these locations … we’re going to keep rolling it out as the state gives us supplies,” Rutherford said.

In the meantime, residents can try making appointments at county-operated sites, hospitals and pharmacies by checking here for availabilities.

San Bernardino County residents aged 65 and older can sign up here to get an email or text notification for updates on vaccination opportunities. 

Those who need help making appointments can call the county’s COVID-19 hotline at 909-387-3911.

In addition to police officers, firefighters and other emergency workers, here’s who can get the COVID-19 vaccine in San Bernardino County: