Around 3000 vaccine doses arrived in the district from Auckland on Friday and were being distributed to general practices.
The CDHB says another 18,000 doses are due to arrive this coming Wednesday and more will be ordered.
Measles is known to be a serious, highly infectious disease which can be life-threatening.
Information has been sent to all Early Childhood Education centres and schools.
The CDHB say that unimmunised people who come within two metres of an infectious person have a 90% chance of contracting the disease.