ROCHESTER, Minnesota: Weeks after the Minnesota Nurses Association pleaded with state hospital CEOs to address a staffing crisis, the Mayo Clinic fired 700 unvaccinated employees.

"While Mayo Clinic is saddened to lose valuable employees, we need to take all steps necessary to keep our patients, workforce, visitors and communities safe. If individuals released from employment choose to get vaccinated at a later date, the opportunity exists for them to apply and return to Mayo Clinic for future job openings," the clinic said in a statement.

The 700 fired employees, who represent 1 percent of the clinic's 73,000 staff, had until January 3 to become vaccinated.

"While final numbers are still not available, nearly 99 percent of staff across all Mayo Clinic locations have complied with the required vaccination program, meaning they have been vaccinated or have received medical or religious exemptions," the clinic added.

Ahead of Christmas, Mary C. Turner, president of the Minnesota Nurses Association and a COVID-19 intensive care unit nurse, said at a 20th December press conference, "To our hospital CEOs and elected officials, please hear us. Nurses need more than words, we need action to address the crisis of staffing and retention in Minnesota hospitals."

Hospitals across the U.S. have been affected by staffing issues amidst the surge of the Omicron variant of COVID-19.

According to Chris Van Gorder, president and CEO of Scripps Health in San Diego, six to eight health care workers are calling the hospital per hour this week to report they have the virus.

"In the emergency departments, we do have patients that are literally stacked up 20 to 30 in some of the hospitals, waiting for an open bed that will hopefully be available when we discharge patients," he told NBC 7 San Diego.

In Rhode Island, the state's department of health updated its guidance to allow COVID-positive healthcare workers to continue working if they have mild symptoms or are asymptomatic, and if their hospital is facing a staffing crisis.

Other states, including New York, where tens of thousands of healthcare workers were fired last year for not complying with vaccine mandates, have called in the National Guard to assist hospital staff.