And another leading scientist says she's slightly nervous about most of the country moving to alert level 1 at midnight tonight, while community transmission remained a risk in Auckland.
The city will remain at level 2.5 until midnight on Wednesday, when it will shift to level 2, meaning gatherings of up to 100 people will be allowed.
In Auckland, face coverings will still be required on public transport and on planes too, from or through Auckland.
For the rest of New Zealand, face coverings will no longer be mandatory but will be encouraged on planes and public transport.
With no new cases of Covid-19 reported today, the total number of active cases remains at 62, of which around half are community cases.
While modelling still suggested there was a possibility of undetected cases in Auckland, that risk was increasingly diminishing.
"The recent run of zero-case days is giving us more confidence that we have contained the cluster - but Auckland shouldn't go all the way to one yet."
Last week, his team calculated that the virus' basic reproduction number - or the average number of people that one infected person could pass the virus on to - was 0.8.
A value kept at less than one generally meant an outbreak could be stamped out.
"The fact we've got small numbers is good news. But we still need to be cautious about the small chance of undetected cases.
"Life shouldn't be going back to that very relaxed period over June and July, and we do need to stay vigilant."
Hendy pointed to the different ways Covid-19 had managed to find its way into the country over past weeks.
University of Auckland infectious diseases expert Associate Professor Siouxsie Wiles also expressed being "a little nervous" after today's announcement.
"I urge all Aucklanders to stick to the restrictions set for Auckland when they travel around the country," she said.
"The Auckland outbreak and the case of the recent returnee show just how tricky this virus is to contain."
But she said that didn't mean New Zealand shouldn't stick with its elimination strategy.
"Rather, we all need to be aware of the symptoms of Covid-19 and be ready to isolate and get tested if there is any hint we may be infected," she said.
"If the country remains vigilant, people wear masks and keep track of their movements, and community testing remains widely available, then we should be able to quickly deal with any new incursions through the border using our test-trace-isolate strategy.
"Adding an additional test for returnees who have left managed isolation would also be a valuable addition to our testing regime."
Since the Auckland cluster was revealed on August 12, contact tracers have identified 3,989 close contacts of cases, of which 3,978 have been contacted and are self-isolating, and officials were in the process of contacting the rest.
Yesterday, laboratories also processed 3,568 tests - bringing the total number of tests completed to date to 914,421.
Cabinet will review the alert levels again on Monday, October 5 on whether moving alert levels at 11.59pm on Wednesday October 7.
