Hospitals are being forced "to take decisions to cease elective care for some points of time – maybe not completely," according to HSE chief executive Paul Reid.
"We are beginning to see the pressure on the resources that is required to address Covid impact on non-Covid care, particularly elective care," Reid said. "A range of elective procedures are being cancelled."
Reid confirmed that the affected hospitals were in Limerick, Navan, Galway, Wexford and Cork, with children's hospitals also cutting elective procedures.
High risk surgeries are being deferred, with University Hospital Galway turning its cardiothoracic ICU into a Covid ICU.
Reid has warned that the coming winter will likely be one of the most difficult faced by the HSE. He called the 93 ICU beds currently occupied as "a serious concern. That is 93 out of 296 beds at the moment."
57% of those in the ICU are not fully vaccinated. Reid urged the unvaccinated to present for their jabs.
"Talking to consultants in intensive care they are seeing younger unvaccinated people in the 30 to 40 age group and sadly some deaths under the age of 25," he said. "We really want to stress that this is a serious illness. You do have a higher level of protection if you are vaccinated. I guess my call to everybody is that we are in a difficult period but this can be turned around quickly and positively."