Ministry of Health figures show it's still taking too long for the contacts of people with Covid-19 to get into isolation.
The Ministry is not reaching its target of having 80 percent of contacts in isolation within four days of their exposure to the sick person.
It's instead managing about 56 percent.
But the figures show contact tracing performance is improving.
Ninety-five percent of an infected person's close contacts were being reached by tracers within 48 hours, well above the 80 percent target.
Epidemiologist Michael Baker told RNZ health reporter Rowan Quinn getting them isolated after that was crucial.