There have been 111 confirmed measles cases in New Zealand this year, 95 of which were people who were not fully vaccinated.
Only eight occurred in people who were fully vaccinated against the disease and the remainder were partially vaccinated.
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Who is most affected by the illness?
Ministry of Health director of public health Dr Caroline McElnay told Newshub it's a priority to have all children vaccinated.
Figures show of the 111 confirmed cases to May 3, 56 were in those aged 19 and below.
"That's why it's really important our national immunisation schedule continues on track and children receive their free routine MMR [measles, mumps and rubella] immunisations on time at 15 months and four years of age.
"We also want to encourage teenagers and young adults who have never been vaccinated to get immunised."
Dr McElnay says the disease can also be devastating for babies, pregnant women, cancer patients and others who are unable to be immunised.
How can people protect themselves?
Two doses of the MMR vaccine can give 99 percent protection against the measles virus, Dr McElnay says.
"One does of vaccine is effective in 95 percent of people, including toddlers," she told Newshub.
The MMR vaccine is free for those aged under 50 who have not had two documented doses.
What should you do if you catch or suspect you've caught measles?
Dr McElnay told Newshub the first symptoms of measles include fever, cough, runny nose and sore, watery pink eyes followed by a blotchy rash.
"If you catch measles you're infectious five days before and until five days after the rash appears.
"If you're feeling sick, you should stay away from work, school or public places, to help prevent putting other people at risk. Isolating yourself will help protect vulnerable people."
What if someone at my child's school has measles?
If there are measles cases at a child's school, children who have not been immunised need to stay away from school until the risk of getting measles has passed, Dr McElnay says.
Can I still get the disease if I'm immunised?
Only about one percent of people who have received both doses of their MMR vaccinations don't develop immunity to the disease.
Are the elderley also at risk?
Dr McElnay says because measles used to be very common, those over 50 are considered immune and don't need the immunisations.
If you or a family member suspect a measles case, you should stay at home and call Healthline on 0800 611 116, or your doctor to alert them of your symptoms