Schools are COVID-19 hotspots and Delta infects more children - so is it time for kids wear masks too?

A public health expert believes New Zealand health officials need to "carefully consider" whether to change the COVID-19 alert level 4 mask-wearing rules for children.

Under the current rules, children under 12 don't have to wear masks in public places while adults do - but in other countries, including the United States, kids are recommended to wear them.

Data shows the Delta COVID-19 variant is twice as infectious as its Alpha predecessor, and countries across the world are reporting more infections in children than earlier in the pandemic as a result.

Add to this that a number of locations of interest are schools, and it begs the question: is it time we made our children wear masks?

Arindam Basu, an associate professor at the University of Canterbury's College of Education, Health and Human Development, says it's something that should be "carefully considered".

"Delta does infect younger people and indeed, school buildings, classrooms, assembly points can be opportunities of spread," he said.

"Masks are good for the purpose of source control, so if you wear masks, then you are less likely to transmit the disease to others."

Prof Basu says wearing a mask is a safe option for children, and notes that the Centers for Disease Control and Prevention (CDC) - the US public health agency - recommends masks for all children above two years.

But he says the question remains over whether this should be mandated.

"For children under the age of 12 years, some authorities consider practical reasons for which they do not recommend it [be] mandatory that the children should wear masks," he said.

"For example, many children under the age of 12 years have problems with adenoids or enlarged tonsils, obstructions in the back of the throat, for which these children cannot breathe well through nose and are oral breathers, so wearing a mask can make them feel suffocated.

"Then there are issues around fogging of the glasses for those with short face size and those who wear glasses with masks on, creating problems of seeing the front of the class and blackboard when the teacher is teaching.

"For very young children - such as those in primary schools and under five years, for example - masks can be suffocating and there are issues around putting them on."

Lesley Gray, senior lecturer at the University of Otago's Department of Primary Health Care and General Practice, says the Ministry of Health's advice around mask-wearing for children under 12 relates to their ability to appropriately put on, wear and take off their mask.

However she says the advice was established during previous outbreaks and under the understanding that in earlier variants, children were less susceptible to COVID-19.

She says with what we know about Delta, children can wear masks if they go out in public, but shouldn't be at alert level 4 anyway.

"Under-12s are exempt from wearing, so will not get into trouble for not wearing one, but families can make choices around wearing masks noting the risks to our littlest ones once we are able to go out and about again," she says.

"If a parent has no choice but to take their child with them to get their essential shopping, a child can voluntarily wear a mask for the short time."

But she says toddlers and babies should not be wearing masks due to the suffocation risks.

The Ministry of Health did not respond to Newshub's questions about whether it would reconsider its advice on mask-wearing for children.