Prime Minister Jacinda Ardern maintains current COVID restrictions have 'greatest impact', no advice red would make 'marked difference'

Prime Minister Jacinda Ardern maintains that mask-use, isolation and vaccination remain key to stopping the spread of the latest Omicron subvariant and that it's unclear whether tougher restrictions will be effective in halting a wave of cases.

For the second day in a row, New Zealand on Thursday reported more than 10,000 new COVID-19 cases, with the seven-day rolling average hitting 8013 - up from 6114 last week. Experts warn daily figures could return to more than 20,000 per day as the BA.5 Omicron subvariant becomes dominant in the community.

Despite the growing number of cases, the Government hasn't announced any tougher restrictions to stem the spread.

Speaking to reporters in Sydney, Ardern said the increase isn't "necessarily unexpected" considering the subvariant has led to a dramatic rise in cases in other parts of the world.

"That's not for a moment to be dismissive or to trivialise the impact on our health system. That's why we'll continue that call; please, everyone does have a role to play.

"We have restrictions and guidelines in place that much of the rest of the world does not. They're not using masks as we continue to and they're not using isolation requirements in the way that we do."

The Prime Minister said modelling shows those measures have the "greatest impact" and said a move to the red traffic light setting, which imposes gathering limits indoors, wouldn't necessarily make a significant impact.

"I have not had advice at this stage that that would make a marked difference to the impact on, for instance, our hospitalisations… But isolation and mask-use do, as do boosters. So, please, if you're eligible - go out and make sure you get that booster shot."

The reason gathering limits may not be effective is because cases are currently primarily among older New Zealanders less likely to be attending big, crowded events.

"Back in the March wave, younger age groups were hit very hard. But actually, the number of cases in older groups was much, much lower," COVID-19 modeller Michael Plank told Newshub this week. "Whereas now, actually, cases in over 70s are higher almost than at any time in the past."

COVID-19 Response Minister Ayesha Verrall told a Health Select Committee on Wednesday it was clear New Zealand is experiencing the "beginning of a new wave" driven by the BA.4 and BA.5 variants. 

"I take that risk of a new wave very seriously and I have been working very closely with the Director-General and the Ministry of Health on the progression of current cases and we keep our response under constant review," Dr Verrall said.

"Let me be clear, none of what we are seeing at this stage guarantees a significant shift to the [COVID Protection Framework]. A successful response to the new wave will be grounded in what is tried and true: getting vaccinated, wearing a mask and staying at home when you are sick."

Dr Verrall said the system would be kept under review, with the possibility of tweaks.

"At this setting in orange, we have available the most effective prevention methods which are masks and vaccines… I want to make it very clear that our emphasis is on these sorts of measures that we currently have in place in orange and looking comprehensively at whether they can be improved."

In a statement on Thursday, the Ministry of Health said there has been a "steady" rise in cases recently. 

"We are continuing to keep our response to the current community outbreak of COVID-19 under review and will adapt it as the outbreak and pandemic evolve, and as part of our resurgence planning."

With school holidays starting on Friday and people heading away, the ministry said families should have plans in place if they catch COVID-19. 

"As with all variants of Omicron, the public health advice remains the same. Getting your booster remains one of the best defences against COVID-19. 

"Stay home if you’re unwell, get tested if you’re symptomatic, wash and dry your hands, cover coughs and sneezes, wear a mask in crowded or poorly ventilated indoor public settings and get vaccinated."