A measles outbreak in the upper half of the North Island has led to a spike in the number of children being vaccinated against the highly contagious virus.
Ministry of Health vaccine distribution figures showed a "significant increase" in demand for the measles, mumps and rubella (MMR) vaccine this year, ministry immunisation manager David Wansbrough said today.
More than 120 cases of measles have been reported since the outbreak began in Auckland in May.
Waikato District Health Board (DHB) yesterday confirmed 17 cases - all in teenagers - in the region, with eight more suspected cases.
Health authorities fear the virus may have spread to Northland after a three-year-old with suspected measles went to day care during the infectious period.
A 17-year-old Taupo girl has also been diagnosed with the virus.
Mr Wansbrough said children needed two doses of the MMR vaccine to be fully immunised - one at age two and the second two years later.
The National Immunisation Register showed 90 per cent of children received the first dose but only 75 per cent had both.
Thirteen of the country's 20 DHBs fell below the national average for the number of children who turned five and had received their age-appropriate immunisations.
Bay of Plenty had the lowest average with 68 per cent, while the lower South Island had the highest rate with 87 per cent.
Common symptoms of measles include a runny nose, cough, sore eyes and fever, followed by a raised red rash that starts on the face and moves to the rest of the body.