Gila County, Arizona, which is located about 90 minutes east of Phoenix, opened up vaccine eligibility to any adult who wants the jab after health officials struggled to find residents within specific categories to vaccinate.
"We were struggling to find folks within the 65 plus category to sign up for the vaccine," Michael O'Driscoll, Gila's director of health and emergency management, told CNN.
Due to this, Mr O'Driscoll made the request for his country to start Phase 2 of vaccine distribution by opening up eligibility to any adult who wanted a jab, and the request was approved mid-February.
The county is made up of 54,000 residents and more than 18,000 have already received the Covid-19 vaccine, according to Arizona's Department of Health Services website. About 86 per cent of doses the county received has been administered to residents.
Overall, 24.9 per cent of the county's population has received at least one dose of the Covid-19 vaccine, as of Friday morning.
Health officials have credited their communications campaign for why they've been able to target residents so quickly to receive one of the available Covid-19 vaccines.
Mr O'Driscoll told CNN the county was using "incident command" structure similar to what would be used for a fire. People in all different communities and departments are working together to help residents get the vaccines.
The pandemic has largely changed in recent weeks in the county, as health officials continue to vaccinate more residents. Cases and hospitalisations were on the decline – statistics that were also being seen across the state.
Only residents of Gila County can currently access a vaccine at one of the county's vaccination sites. But the county said that it would soon open up vaccine eligibility to people who work in Gila County but live in another part of Arizona.