Medical experts say vaccination is the best way to prevent a measles outbreak.

New figures show childhood vaccination rates for measles have fallen - especially in Maori and Pasifika.

GPs fear these low rates and the border opening could result in a surge of cases.

The Royal College of GPs' Bryan Betty told Jack Tame babies can't be vaccinated against the virus, so are at high risk of an infection.

He says vaccination is the best way to protect children, older children, and thus children less than 12 months.