Auckland health officials say they are still nervous about measles, with 77 new confirmed or probable cases so far this month.
The region is battling to control a measles outbreak and has recorded 353 confirmed or probable cases since the end of May.
Sixty-three of the cases that have been confirmed since May have required hospitalisation.
The steady rise in cases prompted health authorities last month to launch new measures to boost immunisation to halt the spread.
The campaign focussed on ensuring infants get two doses of the MMR vaccine by 13 months old, rather than by four years.
Health officials are also encouraging those aged between 15 and 41 to check their own immunisation status if they're unsure.
The clinical director of primary care at Auckland and Waitemata District Health Boards, Stuart Jenkins, says immunisation rates are now 50% higher than they were at this time last year, but the effort must continue.
He says while case numbers appear to be trending down, that should not be seen as a sign the outbreak may be slowing.