Parents are being warned to vaccinate themselves and their children ahead of a potential whooping cough epidemic.
The highly contagious disease, also known as pertussis, is said to work in cycles, with a large-scale outbreak every two to five years.
"Every few years we see a huge spike of pertussis cases in New Zealand, and with the last one starting in 2011 and only just waning now, we can expect another in the near future," registered nurse and former Waikato DHB immunisation coordinator Kim Hunter said.
"We've done a good job of getting lots of adults immunised, particularly parents and grandparents, but in 70 per cent of whooping cough cases in babies, they catch it from a parent or close family member, so we need to keep working to prevent that from happening."
Infants are worst affected by the disease as their airways are smaller, and they are quickly exhausted by the wracking cough that is a hallmark of the condition, she said.
If they are placed in the intensive care unit, they have a one in six chance of suffering severe lung damage, brain damage, or of dying from the disease, she said.
Babies should be vaccinated against whooping cough at six weeks, three months and five months, Dr Helen Petousis-Harris, senior lecturer at the department of general practice and primary health care at the University of Auckland said.
"If you put off vaccinating your baby, all you're doing is leaving them unprotected for a longer period of time," she said.
The warning comes ahead of Immunisation Week, which runs from Monday, April 20 to Friday, April 24. It aims to raise awareness among parents of young children and babies of the importance of immunisation to protect their child against serious illnesses.