There are 80 new cases of Covid-19 in the community today and the South Island has recorded no further spread of the virus after its first positive case in a year was discovered this weekend.

As of 10am, 34 of the cases had been linked - including 16 household contacts - and 46 remained unlinked, the Ministry of Health said.

One of the new cases was in Northland, two in the Waikato and 77 in Auckland. There are no new cases recorded in the South Island after a person who travelled from Rotorua tested positive in Blenheim.

The new Northland case is linked to the four cases announced yesterday in the region. The person was tested as a close contact of one of those cases.

People living in Northland are asked to monitor locations of interest and watch for symptoms.

Testing in Auckland is focusing on areas with higher positivity rates - including Redvale on the North Shore where more than six per cent of tests are coming back positive.

Anyone in Redvale with mild symptoms - even if they were vaccinated - should get tested as soon as possible, the Ministry said.

The same was true for Rosedale where 3.8 per cent of tests were coming back positive. Widespread testing would help identify any undetected spread of the virus.

New Lynn and Bayswater were no longer areas of concern due to a strong response to the call for testing, the Ministry said. People were still encouraged to get tested if they had any symptoms.

Auckland yesterday saw 18,496 vaccinations including 4,391 first doses. Overall 90 per cent of the city's eligible population has had a first dose and 76 per cent have had their second.

The person who tested positive for the virus in Blenheim remains in isolation; two of their household contacts in the South Island town had returned negative tests and were in isolation.

The Blenheim case was not vaccinated, the Ministry said. Case interviews suggested the person's infection was linked to the Te Awamutu cluster and they had a small number of close contacts in Waikato.

Those people had been contacted and were isolating with tests being arranged.

People living in Nelson, Marlborough and Tasman were asked to monitor locations of interest and get tested if they had any symptoms, even if they were vaccinated. Just 144 tests were processed in Marlborough yesterday.

Today's two new Waikato cases are in Te Awamutu and Hamilton and neither has been linked - bringing the total unlinked cases in the region to seven.

Testing is continuing throughout the region, and the Ministry urged anyone with symptoms to get tested, especially if they were in Te Awamutu.

Among the eligible Waikato population, 84 per cent have had a first dose and 67 per cent two doses of the vaccine. There were 2,542 vaccinations in Waikato yesterday including 970 first doses.

One location of interest has been identified in Hawke's Bay after a Waikato case travelled to the region. Anyone at Kmart Napier between 3.53pm and 5.13pm on Friday October 15 is asked to monitor their symptoms for 14 days and get tested and stay home if any symptoms develop. People in the region are also asked to keep an eye on locations of interest.

Fifty people are in hospital including four in intensive care. One of those in hospital is in the Waikato and the rest in Auckland. The average age of people in hospital is 44 years old.

Prime Minister Jacinda Ardern on Friday announced a new traffic light system to manage Covid-19 when the country's 20 district health boards have 90 per cent of their eligible population fully vaccinated.

The traffic light system, which will kick when DHBs get to a 90 per cent double-vaccination rate, will use certificates to allow freedoms for double-dosed Kiwis.

Overall, Auckland has reached 80 per cent fully vaccinated and 93 per cent first doses, so will exceed the 90 per cent target if those people get their second dose.

Wellington and Waitematā are close behind at 75 per cent fully vaccinated, and 91 per cent and 90 per cent first doses administered respectively.

Northland and Tairāwhiti sit at the bottom of the table with 61 per cent and 60 per cent fully vaccinated.

Across New Zealand, 3,626,019 people or 86 per cent of the eligible population have had a first dose, while 2,935,712 or 70 per cent have had a second dose.

Among Māori, 389,884 or 68 per cent have had their first dose while 272,446 or 48 per cent have had their second dose.

In Pacific people, the number of first doses has hit 235,267 or 82 per cent, while 179,554 second doses or 63 per cent have been given out.

Fifty-five people were in hospital yesterday, including five in intensive care. The average age of those in hospital is 43, the Ministry of Health said.

Of the 55, eight are in North Shore, 19 in Middlemore, 27 in Auckland and one in Waikato.

The Blenheim case was a person who flew to the Marlborough town from Rotorua on Thursday.

A small number of close contacts have been identified and are isolating with tests being arranged. No locations of interest have, as yet, been identified.

The Northland cases, which include two first revealed on Friday, are all related to each other and are contacts of a recently diagnosed case in Auckland. Seven of the new Waikato cases are in Te Awamutu and one in Hamilton.