Pima County moved to the Prioritized 1B phase for COVID-19 vaccines Thursday afternoon.
The move means that teachers, educational staff, childcare workers, adults over the age of 75, and protective service workers like those in law enforcement can now sign up for the vaccine.
Pima County opened registration for Priority 1B on Thursday morning and reported that within two hours more than 20,000 people registered to get appointments. The county asked residents to be patient, and said it will open up more slots as it confirms more vaccine availability.
The county is opening four additional vaccine sites in the coming days and weeks. The new sites will be at the Kino Sports Complex, the Tucson Convention Center, the University of Arizona, and Rillito Racetrack.
The state health department is also opening a second mass vaccination site in Maricopa County at Phoenix Municipal Stadium. Reservations are fully booked for the vaccination site at State Farm Stadium in Glendale.
To date, Pima County has dispensed 41,566 doses of the vaccine, including 3,978 second doses. Statewide more than 217,000 doses have been dispensed, including 3,000 second doses, according to the Arizona Department of Health Services.