A group of New Zealand's leading health professionals are pushing for the government to be better prepared for an outbreak of the Omicron Covid-19 variant.
So far, there have been few cases of the highly transmissible variant in New Zealand in the community - the latest being an Auckland MIQ worker.
But Omicron has lead to a dramatic spike in cases globally, including in Australia where more than 100,000 Covid-19 new cases were reported each day for four days in a row last week.
University of Otago professors Michael Baker and Nick Wilson, doctors Jennifer Summers and Amanda Kvalsvig, and University of Auckland's Dr Matire Harwood said the government must "increase measures to delay the arrival of the Omicron variant to give more preparation time".
"We can expect an Omicron outbreak to be very intense."
They suggested an "explicit shift" from a suppression approach to mitigation, and upgrading the alert level system because "ultimately the traffic light system lacks an adequate range of tools".
Baker told RNZ this did not necessarily mean a return to a strict level 4 lockdown: "it might be alert level 3 - a lighter version of that with people working from home if they could".
The timing of the phased reopening of borders was "too early" in their view, despite the government already pushing the first two phases back to an unspecified end-of-February date.
It was also "necessary to greatly reduce the number of infected travellers arriving in [the country]", they said.
The group suggested an urgent tightening of pre-departure testing requirements, which were recently relaxed to allow travellers coming from some places to provide rapid antigen tests (RAT) instead of PCR tests.
"One option would be to add in a requirement for RAT at overseas airports immediately prior to departure, alongside the current PCR requirement 48 hours prior to departure."
There is a "much better chance" of delaying Omicron's arrival if New Zealand can "push the number of active border cases down to a more manageable number", ideally less than five a day, they said. And the use of RATs should play "an increasingly important role", but must be introduced "in a way that supports better decision-making and equity".
Now that RAT tests can be bought privately the group called for "a system that allows members of the public to upload the results of RATs to support ongoing disease surveillance".
Thorough advice and support must be provide for people to manage Covid-19 infection at home the group said, with overseas experience suggesting most of those infected with the Omicron variant could be cared for at home.
This advice should help people recognise if they are "seriously" sick and need additional help, what supplies they should have to manage symptoms, and guidance to minimise household transmission.
They warned that with an Omicron outbreak, "contact tracing will be rapidly overwhelmed ... and soon become ineffective" and measures seen in the previous alert level system might be the "main tools to 'flatten the curve' ".
The group said elimination of the Delta variant was "technically possible" and this would put New Zealand "in a better position if it could be achieved before Omicron starts to circulate widely".
In a briefing earlier today, Prime Minister Jacinda Ardern said New Zealand would move to the red traffic light setting if there was an Omicron outbreak.
"What I expect is over the coming weeks to be able to share with you some of the additional preparation that has been done over and above the work that we did on Delta, for the specific issue of Omicron and what it represents. We have the ability to learn from other nations and see the impact or the way that Omicron is behaving and prepare ourselves."
Ardern said this would mean changes including to the way testing, isolation and contact tracing was done, and the details would be shared in the coming weeks.