UCHealth, the Aurora, Colorado operator of scores of facilities in the state, announced that it will not conduct transplant operations on most patients who are unvaccinated because of an increased likelihood that the patients will die of coronavirus, CBS News reports.

Unvaccinated transplant patients who contract COVID have a 20% to 30% mortality rate, the hospital states, posing an unwarranted threat to the health of the patient.  “This shows the extreme risk that COVID-19 poses to transplant recipients after their surgeries,” the company said in a statement.

According to CBS, Jaimee Fougner, who is donating a kidney to Leilani Lutali, a patient with stage 5 renal failure, said she hasn’t received the vaccine for religious reasons.  Lutali said she hasn’t gotten the vaccine because there are too many unknowns. The women, who met in Bible study, didn’t know about the need for vaccines before surgery until last week.

“At the end of August, they confirmed that there was no COVID shot needed at that time,” Lutali told CBS Denver. “Fast forward to September 28. That’s when I found out. Jamie learned they have this policy around the COVID shot for both for the donor and the recipient.”

The hospital system, however, notes that it has a policy requiring other vaccines, including those for measles and hepatitis B, for transplant patients to give them the greatest opportunity for success.