At least 35 babies in intensive care and hundreds of parents and staff are undergoing urgent COVID-19 testing following an exposure event at Auckland City Hospital's neonatal unit.
On Sunday night, the Ministry of Health said the mother of a baby in the hospital's NICU caught the virus.
Visits to the unit have now been temporarily restricted while hundreds of tests are carried out on babies, parents and staff to ensure they're safe.
"The neonatal intensive care unit has around 35 babies in it at the moment, so we're talking to all those whanau as well as recently discharged families," says Dr Mike Shepherd, provider services director at Auckland District Health Board.
Neonatal Trust CEO Rachel Friend says adding the stress of COVID on top of what families are going through in NICU "heightens that level of trauma even further".
"You never want COVID in any hospital ward, but I think of all the wards for it to have popped up in the NICU is probably the hardest to swallow," she says,
Dr Shepherd is assuring parents the risk to their babies is low.
"There have been other outbreaks in neonatal intensive care units so we've used our international colleagues and understand that the risk is very low to individual infants," he says. "We're confident that we'll be able to manage this."
Meanwhile at North Shore Hospital, a father and newborn tested positive for COVID-19 on Sunday. Several members of staff have been stood down and they're following up with other mothers and babies who may be affected.
Also, a person who went to Auckland City Hospital's Emergency Department on Sunday and was admitted to intensive care has now tested positive for COVID-19. They went to hospital for non-COVID reasons.
There are currently 30 people in hospital with COVID-19 and five in intensive care.
"There's no doubt that in our current outbreak vaccination has prevented people from being hospitalised or dying. Just six percent of cases in this outbreak have had both doses of the vaccine," Director-General of Health Dr Ashley Bloomfield says.
And getting the vaccine is the best way to protect our most vulnerable - those too young to get it themselves.