Christchurch has the highest number of whooping cough cases in the country.
New figures show cases are up by more than 108 percent on the same time last year and more than half are in the Christchurch region.
Dr Fiona Miles and Dr Anusha Ganeshalingham, two Starship paediatric specialists, are warning Kiwi parents to get their children vaccinated against whooping cough.
Whooping cough is a potentially deadly respiratory disease and one of the most contagious.
The specialists say New Zealand's last outbreak of the disease was 2011-2013, with another outbreak due to hit as it cycles every two to five years.
Both are paediatric intensivists who have had to treat babies with critical whooping cough and have had them die in their unit. They say it's extremely traumatic for medical staff and parents when the disease is preventable.
The comments come just a day after a Perth mother has warned of the dangers of whooping cough after her baby nearly died from the disease.
"Those most at risk of malignant pertussis [whooping cough] are those newborns and infants who are unimmunised, they are the four- to six-week-old babies who have never had, or might have had one dose of the vaccine," Dr Ganeshalingham says.
These infants are the ones most likely to develop pneumonia, have a very high white blood cell count and high blood pressure in their lungs. These babies also often need to go onto a ventilator and have blood pressure support.
"When we looked at our 10 year experience, we found that 62 children were admitted to the paediatric intensive care unit with [whooping cough] and 34 admissions were during the most recent epidemic," she says.
Ensuring vaccinations are carried out on time and all family members who come into contact with infants are immunised will help stem outbreaks, Dr Miles says.
"The main group we need to worry about are the very small babies," she says, "newborn babies who are too young to be immunised, and have no protection and have the highest risk of dying from whooping cough."
"I think fathers need to realise that they pose a risk to their babies and need to be immunised," she says.
On-time immunisation with whooping cough vaccine at six weeks, three months and five months of age is one of the most effective ways to protect infants against it.
The vaccination is funded for all children as part of the National Immunisation Schedule and is also free for pregnant women between 28 to 38 weeks.