Leading public health experts say changes to New Zealand's Covid-19 settings are "urgently needed" to prevent "huge waves" of Omicron infections.
The blog post has been authored and released by Professor Michael Baker, Dr Jennifer Summers, Dr Amanda Kvalsvig, Dr Matire Harwood, Professor Nick Wilson.
They say while Delta cases have steadily declined in New Zealand, the threat of an Omicron outbreak has "increased markedly".
"NZ is seeing a huge increase in cases being detected at the border and in MIQ," they say.
Figures from the Ministry Health reflected this, with a large jump in cases arriving at the border since December 2021.
"A poorly controlled Omicron outbreak in NZ risks overwhelming the health care system, increasing inequities, and disrupting essential services as is being seen overseas."
They called for several measures to be introduced immediately.
This included taking rapid action to "turn down the tap in the number of infected cases arriving in New Zealand" and tightening pre-departure testing requirements.
"These were recently relaxed by expanding the list of countries where PCR testing was no longer mandatory, and a rapid antigen test could be used instead."
That list included Australia, which was dealing with high numbers of Omicron cases.
The health experts also called for as many people to receive booster shots as possible, as well vaccinations for 5-11 year olds, which began today.
"The roll-out of boosters and vaccination of children is a particularly important opportunity to prioritise delivery to Māori, Pasifika, those with underlying illnesses, and other at-risk populations such as those in aged-care residential facilities."
They also called for an "upgraded alert level system".
"The traffic light system is largely orientated towards achieving an indoor vaccine mandate. This system is now less effective since the vaccine passes are based on people being double vaccinated rather than having a booster as well. This limitation could be fixed in time but ultimately the traffic light system lacks an adequate range of tools."
They said that contact tracing would likely be "rapidly overwhelmed" in an Omicron outbreak.
Other measures included stronger mask wearing rules, including advice that people should move to higher quality N95 respirator style masks when indoors with people during an Omicron outbreak.