As winter's cold bite starts to settle in - bringing the seasonal flu and Covid-19 infections - parents and schools are being encouraged to get children vaccinated against Covid.

Epidemiologist Professor Michael Baker says a proactive approach is needed in this current pandemic environment - particularly as we head into winter.

"We all know the problems we're up against," he told TVNZ this morning.

"We know what's going to come over winter. It's all about protecting the children, their health, the teachers who have high rates of long Covid - in the UK, that's really emerging."

Getting youngsters vaccinated against Covid also helped to protect the rest of the family should a child come home from school with the virus.

He acknowledged then that those living in multi-generational households needed to heed that vaccine advice, in particular.

"It's just going to put a handbrake on the virus over winter, when we're looking at a really big peak of Covid-19, flu, RSV [Respiratory Syncytial Virus] and so on."

How schools can help promote better health

Baker spoke about the importance of the school community and the role schools play in this current situation.

The Ministry of Health's latest data shows that of children aged between 5 and 11 who are now eligible for Covid vaccines, about 25 per cent had had two shots.

Baker said the fact that vaccination rates among those young children were still "too low" was a key aspect that needed to be looked at more carefully.

"Can we use schools more proactively to raise vaccine coverage?"

He also pointed out that children were very good at adapting and learning health-promoting behaviours such as being sun-smart, understanding cough hygiene and hand-washing - the latter being something children were sometimes better at doing than adults.

"They can also be really good at mask-wearing."

New My Vaccine Pass app now active

Baker's comments come as the new updated My Vaccine Pass officially becomes available today.

People who are up-to-date with their Covid vaccinations will be able to download a new-look My Vaccine Pass that authorities are still encouraging, despite it no longer being a legal requirement.

With the update comes a new colour - blue - and will be available to anyone aged 12 years old and over who has had all their respective Covid shots. It includes booster vaccinations for those over the age of 18.

Health Minister Chris Hipkins said at the time of the announcement of the new app that there may still be some places where the passes will be required.

"We've learned over the last couple of years there are no certainties with Covid-19 and with new variants circling the globe, it's best we're prepared for every eventuality."

The updated My Vaccine Pass will be valid for six months from the date of issue and can be requested any time, provided that person is up-to-date with their shots.