About 15 percent of nurses at Canterbury District Health Board (DHB) are off because of Covid-19.
And 18 percent of health workers at a Porirua Hospital are absent as the impact of the outbreak continues to grow outside Auckland.
Nurses were the hardest hit health workers at Canterbury DHB but allied health workers - including medical technicians, physiotherapists and lab workers - were not far behind with 13 percent of them off.
And 9 percent of doctors were affected.
Canterbury DHB incident controller Helen Skinner said, in total, about 510 staff were off either with Covid-19 or as a household contact.
Staff left behind were going "above and beyond" to help keep essential services running, she said.
Part-time workers were working extra shifts, full-time staff were doing overtime, and people were being redeployed to areas where there were shortages, she said.
About 15 percent of people turning up to the emergency department had Covid-19.
Wellington's hospitals were also dealing with significant numbers of clinical staff off because of Covid-19.
Nearly 500 health workers were off at Wellington Regional hospital, about 14 percent of a staff 3500.
And 18 percent of the 340 health staff at Kenepuru Community Hospital in Porirua were off, with six percent off at Hutt Hospital (out of 1640 staff).
At Lakes DHB, which included Rotorua and Taupō Hospitals, 8 percent of the clinical workforce was off because of Covid-19.
Nursing staff there had been bolstered by the return of about 20 nurses from Rotorua's managed isolation hotel, a spokesperson said.
At Taranaki DHB, 4 percent of staff were off because of the virus, there were 2.5 percent off at Northland and just under 5 percent at Hawke's Bay.
In Waikato, 214 out of about 8000 staff were off, most of them clinical
It was seeing a drop in the number of patient coming through its emergency department with Covid-19 - just 3.3 percent on Tuesday, down from 7.3 percent a week prior.
Southern DHB was less impacted, with 92 staff out of 5000 off because of Covid-19, but community cases were still rising in the region.
There were just 46 people off in Whanganui.
Patients can't be put at extra risk - Nurses Organisation
Nurses say they fully support the changes the government announced yesterday, including maintaining the mandate for nurses.
President of the Nurses Organisation Anne Daniels, who works in the emergency department at Dunedin Hospital, is aware of the risks staff would be placing on patients and each other if the mandate was not in place.
Daniels said the percentage of health workers who refused to be vaccinated was very small although the loss of a single nurse or doctor had an impact in a workforce that had been short-staffed for 16 years.
Health professionals had an obligation to keep their patients safe so it was crucial they were all vaccinated and they would not want to be working alongside a small number who weren't.
"We do very very hands-on care so we can't keep the two metre distance ... we do all the required things but there is still a risk.
"We cannot be put in a position where we put our patients at extra risk - they are already unwell."
The pandemic was continuing to place pressure on the country's health system and the Omicron outbreak had added further pressure with staff catching the virus.
The $500 payment to nurses in Auckland to do extra night shifts was "the tip of the iceberg" and showed the desperation of DHBs needing nurses to come to work, Daniels said.
The government had also recognised the importance of nurses by reducing the number of days nurses have to isolate and even allowing them to return to work with mild Covid-19 symptoms.
RNZ
