Riverside County health officials are opening COVID-19 vaccine clinics Thursday for those 65 and older as well as certain essential workers.

The county has made the vaccines available to essential workers like educators, dentists, mortuary staff, food and agriculture workers, pharmacy staff and those in emergency services — in addition to frontline health care workers and older residents.

The new walk-up vaccine clinics were set up at Corona High School in Corona, Heritage High School in Menifee and San Gorgonio Middle School in Beaumont. They will operate 8:30 a.m. until 4:30 p.m. Monday through Friday.

Another site will open at the Indio Fairgrounds on Sunday.

And on Saturday, a drive-up vaccine clinic at Lake Elsinore’s Diamond Stadium will open only for residents aged 65 and older from 8 a.m. through 3 p.m. at 500 Diamond Drive. Seniors who need help making an appointment can call 800-510-2020 or 2-1-1.

Residents were told to sign up for an appointment at ruhealth.org, but as of 1 p.m. Thursday, all vaccination sites were listed as “full.”

Everyone looking to get vaccinated has to register prior to arrival and show proof of eligibility, like badges or letters from employers.

Those eligible for the vaccine in Riverside County can also sign up to get their shots at Albertsons Pharmacy, Apple Urgent Care and Ralphs Pharmacy.

“The county team is moving quickly to open more sites that will vaccinate even more of our residents,” Supervisor Karen Spiegel said in a statement. “We know so many of our residents want the vaccine and we’re working diligently to make that happen.”

Riverside County has so far administered about 33,400 doses of the more than 114,800 doses received, according to county data updated Wednesday.

California state officials on Wednesday announced that everyone 65 and older could receive the COVID-19 vaccine.

But supplies remain scarce and not all counties are ready to expand vaccine eligibility beyond health care workers.

That’s the case in Los Angeles County, where there are hundreds of thousands of health care workers who have yet to be vaccinated and there aren’t enough doses to inoculate those 65 and older, according to the county’s health director.

Orange County on the other hand is vaccinating residents 65 and older, including at a COVID-19 vaccination “super” site that opened at the Disneyland Resort Wednesday. Appointments can be made online.

San Bernardino County officials say the county is on track to begin vaccinating residents 65 and older soon “if progress and supplies remain on track.”