Health researchers warn the lack of Covid protections in schools is unacceptable and could drive another outbreak of the virus.
In an editorial published in the New Zealand Medical Journal on Friday the researchers said events in 2022 showed schools were high-risk settings for infectious diseases and teachers' safety was significantly compromised by a lack of protections.
They said most school children caught Covid last year and teachers had the highest rates of infection of any occupational group.
The 11 authors, including Amanda Kvalsvig and Michael Baker from the University of Otago, called for a switch to a science-led, whānau-centred response.
"Aotearoa New Zealand's policy of "business-as-usual" school-based infection control resulted in serious and inequitable impacts on health and education during 2022.
"There is an urgent need for New Zealand to reorient its school policy to protect students, staff and whānau in the current era of ongoing new Covid-19 variants," they said.
The article said the government last year emphasised the importance of face-to-face attendance at school but did not require mandatory use of face masks or provide sufficient air purifiers to ventilate all classrooms.
The article said 66 percent of five to 19-year-olds tested positive for Covid between February and the end of September last year.
Forty percent of school teachers had tested positive for the virus by the end of July last year, it said.
The researchers said in-school transmission helped to drive outbreaks of Covid and did not simply reflect community cases.
Studies in the US consistently showed Covid case numbers were lower in schools with mask policies, they said.
'We do need to start now'
University of Otago Wellington research associate professor and lead author of the article, Amanda Kvalsvig, told RNZ the government must act quickly.
"The work to put this right needs to begin straight away with a commitment from government to protect students, staff, and whānau," she said.
"Without active prevention, we can expect ongoing disruption that will be very hard to manage.
"There's no justification for continuing with business as usual and hoping the health and education impacts will go away. From studying what's happening outside New Zealand, we know they won't."
The article said the government's school policy during 2022 leaned heavily on a single report that stated schools were not a major driver of Covid-19 transmission when other settings were open and that persisting symptoms in children resolved by eight to 12 weeks.
It said schools needed good ventilation and access to a well resourced system for online or hybrid learning.
"These protections should be embedded within the school system and within New Zealand's next pandemic plan as they may be needed each year during the winter respiratory season or at short notice during a public health emergency," it said.
"Cumulatively, if not addressed, the impacts experienced in 2022 and beyond may contribute to a measurable future deterioration in the health of New Zealanders and the sustainability of the education sector."
Kvalsvig told RNZ the goals suggested by the researchers were highly achievable.
"Looking at the actions needed to achieve them, we can sequence them from immediate solutions that we know will make a difference right away - eg, every classroom must have appropriate equipment to monitor and improve air quality - all the way along to more permanent infrastructure such as highly effective mechanical ventilation," she said.
"If government steps up to make this commitment, the day will come when infectious disease outbreaks in schools become a thing of the past. We'll be learning as we go, but we do need to start now."
'Plan for the inevitable'
Another of the editorial's authors, professor Michael Baker, told RNZ it was important to acknowledge that schools were a higher-risk setting for transmission not only of Covid-19, but also of respiratory syncytial virus (RSV), influenza and potentially measles and pertussis.
It was important schools planned ahead to minimise risk by ensuring classrooms had adequate ventilation and low-cost CO2 monitors in place, he said.
"We know these (outbreaks) are inevitable, we've had one school already in the Wairarapa in February that had to shut and switch to online learning."
Having robust contingency measures in place to enable a smooth transition to online learning if required, and to ensure sick children did not attend school, was also crucial, he added.
"I think it's much more sensible and realistic to plan for the inevitable and do it in advance, in a proactive way," Baker said.
"It's part of resilience to all kinds of problems ... not just pandemics, but flooding and earthquakes and so on, this is part of having really resilient schools."
School teachers were highly exposed to Covid-19 through their work and mask-use could be a useful tool in the event of an outbreak, he said.
"I don't think they should be used routinely, but if you're seeing high rates of infection, yes, I think they become important."
Baker said he thought it was "quite likely" the country would see another major wave of omicron infection this year, given the way the virus was behaving.