More than 100,000 measles vaccines will be handed out in Canterbury over the next few weeks.
There are currently 25 confirmed cases within the region, with the DHB saying it can be assumed that measles is circulating widely within the community.
It's caused a huge demand for the MMR vaccine.
A Canterbury Medical Officer of Health Dr Alistair Humphrey told Mike Hosking they have unprecedented numbers of vaccines to give.
"We have got GPs talking ab out 5000 a day for a few weeks, that is an enormous number."