An epidemiologist is warning the Government should delay allowing children to return to school until enough young people are vaccinated.
Dr Amanda Kvalsvig, at the Department of Public Health at the University of Otago, Wellington, said Omicron had triggered an avalanche of child cases overseas, at higher rates than previously seen in this pandemic.
"Schools and hospitals are struggling to manage the high rates of infection and there are rising concerns about post-acute effects in children, including Long Covid and an increase in autoimmune problems like diabetes.
"Here in New Zealand we have an opportunity to break that pattern, but we need to be decisive and move fast," Kvalsvig said.
Her comments come after Education and Covid Response Minister Chris Hipkins told the Herald he wanted kids back in class fulltime this year to avoid more disruption to their learning. Cabinet was due to next review its plans when it met on January 17.
Kvalsvig said there were a number of key protections that needed to take place before sending children back to school.
That included high vaccination coverage among all school-aged children, effective ventilation in schools, high-grade masks, access to rapid antigen testing (RAT) and support to stay at home.
"Worldwide and in NZ, children are the least-vaccinated age group. This immunity gap needs to be closed as quickly as possible," she said.
New Zealand school buildings were generally poorly-ventilated, Kvalsvig said.
"An important first step is to use carbon dioxide (CO2) monitors as a way of alerting teachers and students when the air has become stale from too much rebreathing."
Virus particles could then be filtered out of rooms using HEPA filters.
The public does not yet have access to RAT tests or information about how best to use them and this was crucial to protect children, Kvalsvig said.
To stop school outbreaks, children also needed to be able to stay home if they had symptoms or tested positive, Kvalsvig said.
"That means that working parents need sick leave support to stay home too, and children who're at home for longer than a few days will need educational and social support."
New Zealand Educational Institute president Liam Rutherford said they would be guided by public health advice.
"I don't think anyone working in schools is under the illusion that Covid is done and dusted, and we fully expected as we head into the year that we are going to be dealing with the twists and turns it's going to bring."
He schools were prepared for more localised responses.
"We know that heading into this year that there will be a big push around getting children between the age five and 11 vaccinated and we are looking forward to rolling up our sleeves and doing our bit.
"As you'd expect there is quite a diverse set of opinions among parents but we do know they want to have the confidence to send their children back to school safely."
Speaking to the Herald before Christmas about the 2022 school year, Hipkins said he wanted stability and full attendance to be the norm, with disruptive measures like alternating days at school only used on local level in case of an outbreak.
"I want the kids back in the classroom sooner rather than later because we certainly wouldn't want them to lose any more in-person learning time".
He anticipated there would be a high threshold before officials would consider closing a school.
"A couple of cases generally wouldn't be enough to trigger it."
The Minister was banking on high vaccination rates making schools safe. Since January 1 all staff had to double-jabbed and secondary school students' vaccination rates were also expected to hit 90 per cent before the start of Term 1, which he said would provide "a good layer of protection".
Pfizer's vaccine for kids aged 5-11 would be available from January 17, with 476,000 children eligible from that date.
But even after vaccinations, Hipkins said public health measures would still be in place with measures like indoor masking and cohorting - limiting mixing between class groups - likely to be around for a while yet.
Tahuna Intermediate principal Simon Clarke said this year would be ''much harder'' than last.
"Last year was stressful because we have been trying to keep it out of our schools and keep everyone safe.
"The next part will be when we're actually trying to deal with it within our schools, and teachers are getting sick, children are getting sick, and trying to keep the school open, which I think is what the ministry want us to do."
A Ministry of Health spokesman said a range of public health measures were in place to keep children protected from Covid-19 at school.
At this stage there were no plans to introduce mandatory surveillance testing in schools.
"However, we will continue to closely monitor cases in schools and as with all aspects of our Covid-19 response, we will make improvements as necessary based on any information and evidence.
"The Ministry of Health's Omicron planning is well under way, which includes managing exposure events in schools, recognising the increased infectiousness of the Omicron variant, and will be made available in due course."
Duty minister Grant Robertson said the Government was constantly reviewing the Covid-19 response, particularly in light of Omicron. At this stage schools will reopen as planned.
Vaccination remained the best defence anyone had against getting sick from the virus and he encouraged parents to get their children vaccinated.