OKLAHOMA CITY (KFOR) – While many families are preparing to gather for the holidays, health experts are warning about the increasing number of hospitalizations related to the coronavirus.

On Tuesday, the Oklahoma State Department of Health reported 621 new COVID-19 cases in the Sooner State.

Officials say there were 686 Oklahomans hospitalized with COVID-19 on average over the past three days. Authorities also noted that there were 13 pediatric hospitalizations for COVID-19 included in that number.

Officials say most of the hospitalizations are related to the Delta variant, adding that the Omicron variant that is spreading across the globe has not been detected in Oklahoma yet.

According to the Oklahoma Hospital Association, 91% of hospitalized COVID-19 patients are unvaccinated.

At this point, experts say hospitals are concerned about staffing since they are already short-handed on nurses and other clinical caregivers.

“Once again, staffing is our greatest concern. You’ve heard us say before that our that our bedside staff are leaving to go to work for contract agencies or less stressful jobs. We are hearing from contracted staffing agencies that they are even struggling to find enough staff to meet the demand that hospitals are placing,” said Patti Davis, president of the Oklahoma Hospital Association.

Doctors are encouraging Oklahomans to get their booster shots and wear masks in public settings to reduce exposure to the virus.