Officials urged any eligible person to sign up for immediate COVID-19 vaccinations at the huge California State University, Los Angeles, site because relatively few appointment slots were filled.

“We’re light on appointments for the next several days. We want to finish strong and use up every dose we have,” Greg Renick a spokesman for California’s Office of Emergency Services, told the Los Angeles Daily News on Wednesday.

The Cal State LA site was established by the Federal Emergency Management Agency and Cal OES. The city of Los Angeles will take over its operation next week.

It was unclear why so many slots were open at the site, which is offering the one-dose Johnson & Johnson vaccine, the Daily News said.

The site offers drive-thru, walk up and mobile vaccine options.

The Cal State LA site and another one in Oakland were announced as pilot projects by the Biden administration in February.

Cal OES said that as of Monday, the two sites had administered nearly 625,000 vaccines, including thousands delivered to communities by mobile clinics.

California has surpassed 20 million total vaccinations, the governor’s office announced this week.