Sinema and Kelly asked the Biden administration for an immediate supplement of 300,000 vaccine doses with an additional 300,000 doses added to Arizona's usual weekly supply.
This comes after Sinema's request from last week asking the Dept. of Health Services and FEMA to provide more vaccines.
Several other lawmakers, including Gov. Doug Ducey and congressman Greg Stanton, have also made similar requests.
This comes as President Biden is expected to take a virtual tour of the 24/7 COVID-19 vaccination site at State Farm Stadium in Glendale.
"Today, the President will see firsthand Arizona's need for a significant increase in vaccine doses," Sinema wrote in a statement. "I look forward to continuing to work closely with the administration on our request for more vaccines - both at our state-managed vaccination sites and at other distribution sites across all 15 Arizona counties."