An epidemiologist says it is still too early to know what effect the stricter measures have had in curbing the spread of COVID-19 in the community, but is optimistic the cluster can be controlled.
There were nine new cases in the community on Monday, and 13 on Sunday.
Seven of the nine cases were linked to the Auckland cluster, while two were under investigation but believed to be linked to the existing cluster.
That brings that total number of cases under investigation to four.
"These results are very encouraging. We appear to have just one large cluster, the case numbers are not accelerating despite monumental amounts of testing," Otago University epidemiologist Michael Baker told Morning Report.
He said it showed the benefits of ramping up capabilities for high volume testing, contact tracing and now the use of face masks.
"We're in a much better situation than we were back in March."
But he said Auckland would have to wait a few days to gauge the situation and move alert levels because the numbers at the moment reflected transmission before the city went into lockdown or just after.
"Given the number of cases, it is still a large cluster. We don't know if there are other cases outside it, we don't know the source."
The settings at the moment were good, and case numbers by the end of the week would be able to determine a change in alert levels.
"This is looking like we will get this under control. We can control a cluster and we can eliminate this disease again without ever discovering the source of this particular cluster."
But it would be great to know the source, he said, which would be valuable to prevent the same episode repeating.
Baker said New Zealand was doing a good job trying to eliminate the virus, but the country had only been in a reactive state the past six months.
"It's time for us to be proactive ... once this outbreak is under control, which I think will happen."
As for some Year 12 and 13 students returning to the classrooms, Baker said older students were more likely to behave like adults and help reduce transmission of the virus.
He said at level 3 face masks should be used in schools.
An alert level 1.5 was a good idea to keep the virus out of the community, he said. Moving from level 2 to level 1 created a space for big events to be held which could amplify the spread of the disease.