At Darfield High School, some classes had absence rates of 40 per cent.
Principal Andy England said last week there were currently 11 students and one staff member absent with Covid-19, but many more students off school with coughs, colds and influenza-type symptoms.
The school rostered some classes home for online tuition as Covid peaked last term. So far this term the school had avoided rostering home.
"Staff numbers affected by Covid come and go, and we are constantly close to needing to roster home due to lack of cover for classes.
"We will continue to try our best to avoid this, as we really want settled learning time,” England said.
Lincoln High School principal Kathy Paterson said about 2 per cent of staff and students were currently home as they tested positive, while the number self-isolating was "much higher".
"Absence rates for Covid-related absences have, in general, been lower than they were in term one. School is operating as per normal so far this term," Paterson said.
Ellesmere College and Rolleston College reported they had low numbers of staff and students away due to Covid-19.
Ellesmere principal Ronan Bass said colds and flus were no higher than in pre-Covid times.
It comes as the Ministry of Health warns of new Covid variants, flu, and other infectious illnesses for what will be "a challenging winter" ahead.
Clinical adviser Joe Bourne said it was likely this season would see increased pressure on the health system with the possibility of more Covid and influenza in the community, as well as illnesses we haven’t seen for some time, such as measles and whooping cough.
"After two years of closed borders, our immunity to these illnesses will be low and we need to do all we can to keep ourselves and our whānau healthy," Bourne said.
At the same time, Covid-19 modellers are predicting a new wave of the virus, most likely peaking between August and November.
And cases of flu are spiking across the Tasman. A rapid 130 per cent jump in flu cases early in the season prompted Queensland authorities to offer people free vaccine jabs.
University of Queensland virologist Ian Mackay told RNZ the spike was happening before the usual increase which happened in cooler months.
Usually, there’s a gradual increase in flu cases over the cooler months. But that doesn’t seem to be the case this year.
Mackay said we’re experiencing a spike in cases early in the year.
"Some of that is due to increased lab capacity for flu testing, but the rate itself - or the amount of positives per number of samples tested - suggests a spike as well,” he said.
"We usually see a bit of a baseline, the foothills of the mountain if you like, as the season comes into play.
"But this time we’ve gone from zero to full-on and it’s not clear how high this peak will be, nor how long the flu season will last.
"So if you’re looking to get vaccinated, now’s the time to get it."
