Parents in Auckland are being urged to immunise their children ahead of the school year following a spike in whooping cough cases.
Between November last year and January, 52 children in the Auckland region were hospitalised with the highly infectious disease.
At the end of last term, 47 schools and early childhood education centres were forced to manage children with whooping cough, often excluding them to prevent its spread.
Those most at risk were infants aged under one year old.
This is the second whooping cough spike in Auckland, the last being between 2017 and 2018.
Michael Hale from the Regional Public Health Service said whooping cough is a serious illness, and it's important children are up to date with their vaccinations.
"Children with whooping cough cannot go to school or early childhood centres for up to two weeks unless they receive antibiotics," he said in a statement.
Dr Hale said cases of whooping cough must be kept away from schools and childcare to prevent further spread.
The vaccination is free for those under 18-years-old and for women in their last three months of pregnancy to protect their baby once it is born.
What to look out for
The Auckland Regional Public Health Service said whooping cough started like a cold with a runny nose, cough and fever.
After a week that coughing would become more severe and prolonged, and might end with a whoop, dry retch or vomit.
If a person suspects they, or their child has the disease, they are advised to call their GP or Healthline on 0800 611 116.