There is one new Covid-19 case in managed isolation today, the ministry of health says, and there are no cases in the community.

In a statement today, the ministry said the new case in managed isolation arrived in the country from Cambodia via Singapore on 25 June.

It also said one previously reported case has now recovered.

Three previously reported cases have now been reclassified as under investigation pending a historical classification investigation, the ministry said.

"These involve a case from India reported on 26 June, a case from South Africa and another from India both reported on 28 June. These cases have now been removed from New Zealand's Covid-19 tally."

Of the 2673 total contacts of the Covid-infected tourist who visited Wellington, 97 percent have returned a negative result. Fifty-two contacts have still not been tested nor had a clinical exemption.

The number of active cases in New Zealand is 28 and the total number of confirmed cases is 2384.

In Australia, New South Wales has recorded 24 new locally acquired cases in the 24 hours until 8pm yesterday, while Queensland has recorded two new community cases of Covid-19.

Travel to New Zealand from all of Australia - which has continued to report new community cases and has about its population in lockdown - remains closed until 11.59pm on Sunday for lower-risk states, and until at least Tuesday for higher-risk states.

Wellington update

The ministry said so far, 2673 people have been identified as contacts of the Australian person who visited Wellington between 19 and 21 June.

"Of those 2673 total contacts, 2583 or 97 percent of people have returned a negative result, and an increase of 78 negative test results since yesterday. An additional four people have had a swab and are awaiting a result, 19 people have been granted a clinical exemption, seven require no further action, and eight have returned overseas, which means their home jurisdiction will be following up with them.

"The remaining contacts are being actively followed up by contact tracing teams."

The ministry said following Sydney traveller's visit, Wellingtonians and recent visitors to Wellington are urged to check the locations of interest of possible exposure from Saturday 19 June to Monday 21 June and follow the health advice.

"People who have been at these locations of interest at the specified time should immediately isolate at their home or accommodation and call Healthline (0800 358 5453) for advice on testing.

"At this stage, you do not need to be tested or isolate if you were not at a location of interest, unless you have symptoms."

The ministry reminded New Zealanders that anyone who was symptomatic should call Healthline on 0800 358 5453 for advice on testing.

Yesterday there were 7775 Covid-19 tests processed and the total number of Covid-19 tests processed to date is 2,296,650.

The Covid-19 Tracer app now has 2,882,517 registered users.

In a vaccine rollout update yesterday, Covid-19 Response Minister Chris Hipkins said New Zealand was tracking about 8 percent ahead of its vaccination plan and less than a day's worth of vaccines were expected to remain in government freezers by the time the next shipment is due to arrive on Tuesday.

A new study also showed herd immunity against the Delta strain would be nearly impossible to achieve using vaccines alone.

Covid-19 data modeller Shaun Hendy said other public health measures - like border closures, mask use, contact tracing and hand washing - could bolster the response, and Director-General of Health Dr Bloomfield said higher uptake of the vaccine would allow a reduction of reliance on those.