All Oklahomans over the age of 16 will be eligible to receive the COVID-19 vaccine beginning Monday, March 23, according to state health officials.

Oklahoma State Department of Health Deputy Commissioner of Health Keith Reed made the announcement in a press conference Tuesday morning.

Phase 4 of the state’s vaccination plan expands access to a COVID-19 vaccine to about 555,200 residents who were not covered in earlier phases, according to the state’s estimates. “We have all been looking forward to this day for a long time,” Reed said.

Oklahoma has consistently been a leader among other states for vaccine doses administered by population, bolstered by vaccination efforts from tribal nations — several of which have already opened eligibility to anyone, regardless of tribal affiliation or residence — and federal providers like Veterans Affairs.

According to Reed, 1,674,556 doses have been administered in the state, and 1,081,578 Oklahomans have had at least one dose.

Tuesday’s announcement came two weeks after the state opened up eligibility to the vast majority of adult Oklahomans on March 9 by expanding access to essential workers, college students and people who work in educational settings, among others. Those groups, making up Phase 3 of the state’s plan, include roughly 2.4 million people.

The Pfizer vaccine is approved for those 16 and older, while Moderna and Johnson & Johnson’s vaccines are for people 18 and up. Vaccine trials are still underway for children.