A measles outbreak in Hamilton has spread to a second high school where unimmunised students are being asked to stay home.
Thirty-eight cases are confirmed in Waikato and a further 20 are under investigation in an outbreak linked to Fraser High School. More than 200 students of its students are quarantine
Waikato District Health Board said there a case of measles had now been confirmed at Hamilton Girls High School.
Letters had been sent to parents asking them to provide records about their child's immunisation status, and to keep their girls in quarantine at home if they're not fully immunised, or if they're unsure whether they have been immunised.
Medical Officer of Health Anita Bell said parents at both schools were being asked to provide details about their child's immunisation status but others also needed to take action.
"Just a message to all under 20s - if you're due for your immunisations, get them. If you haven't had them yet, get them."
Dr Bell said those regarded as not immune were people who were under 45 who had not had two doses of the MMR vaccine or had not had lab-confirmed measles.
Also not immune were children over four who had not yet had a second dose of the vaccine, and babies under 15 months and had not yet had their first dose.
Two doses of the MMR vaccine are needed for full immunisation against measles, which is a potentially serious disease.