While most American adults have been vaccinated, people in some states are still hesitant to get their shots.
In Missouri, hospital space is now a concern as COVID-19 cases go up.
"Should we start to see a high number of COVID patients like they are there, we're going to be very challenged with how many beds that we have available," Steve Hoeger of the MARC Health Care Coalition said.
A Springfield, Missouri, hospital has opened its sixth COVID-19 ward as the delta virus variant rages in the state's southwest region.
Chief Administrative Officer Erik Frederick says the hospital needed at most five virus wards last year. Frederick has tweeted that many people in local rural areas are unvaccinated.
He also says people from rural areas don't have nearby hospitals, so they come to Mercy Hospital in Springfield.
About 56% of adults in Missouri have gotten at least one vaccine shot. That vaccination rate is about 12 points lower than the national rate.
Simon Kaufman and Alex Livingston contributed to this report.