Medical practices in Northland without the measles vaccine will have to wait next week and prioritise children 2 years and under, the Ministry of Health says.
Unprecedented demand for the MMR vaccine throughout New Zealand had led to a shortage and forced GPs in Northland to reschedule bookings for those wanting to be vaccinated.
A shipment of 52,000 vaccines is due in New Zealand this weekend and will be distributed where needed, including GP clinics throughout Northland, from next week.
The number of confirmed measles cases in Northland stood at 40 as of Wednesday and a further seven cases are under investigation.
An epidemic has been declared in Auckland where 959 cases have been confirmed of the more than 1000 throughout New Zealand.
Director General of Health Ashley Bloomfield said following advice from an immunisation expert advisory group and feedback from general practices, the ministry was asking GPs and PHOs to target measles vaccinations to the most vulnerable.
He said general practices have responded extremely well to the demand for MMR vaccine but have reported that in some places, vaccines weren't reaching those most in need of protection, which included children aged 15 months - or 12 months in Auckland.
The ministry has given 160,000 vaccines throughout New Zealand this year compared to 90,000 during the same period last year.
"Children aged 2 years and under are more likely to be hospitalised because of measles so it's imperative they're vaccinated. First and foremost we need to protect our children," Bloomfield said.
He said the first priority should be to ensure all children across the country received their vaccines on time at 15 months, or 12 months in Auckland, and 4 years to maintain the national childhood immunisation schedule.
Bloomfield said children aged up to 14 years who have not had a single dose of vaccine would be contacted.
Advice on measles can be found on www.health.govt.nz/measles-advice.