The state government last Saturday changed its stance on masks, making the "strong recommendation" children aged five and up wear masks outside the home, including in the classroom.

The change was a response to the high rate of transmission of the COVID-19 Delta variant in young people but Professor Nathan Grills said the recommendation needed to be scrutinised more closely.

"In a high-risk scenario encouraging children to wear masks is probably proportionate because masks do make a difference to spread," he said.

"But I'd say if you're in Warrnambool and you've got zero cases it is disproportionate."

Professor Grills said it was particularly problematic in a classroom setting where it was possible masks could do more harm than good.

"If a person wears a mask correctly, then yes it will have a benefit, but the chance of that happening for a primary school aged kid over an eight-hour day is zero," he said.

"A small child trying to learn while wearing a mask, when it will have very little additional benefit, is probably disproportionate."

Most parents seem happy to let their child make the choice on the new recommendation, with some children embracing the chance.

Beth Parker said she was surprised when she discussed it with her nine-year-old daughter, Eliza.

"When the announcement was made Eliza said 'do we have to wear masks?' I said it was just a suggestion but she was like 'no I really want to'."

Ms Parker said there would be some young children who would find mask-wearing a challenge but she was happy to follow the recommendations.

Local primary schools were also happy to heed the new suggestion.

Great South West Government Schools network chair Marina Milich said "everybody is just following the health advice".

"We appreciate mask-wearing for primary age students is recommended, not mandated, and we support parent choice."

President of the Victorian Association of Catholic Primary School Principals Michael Gray said schools were providing masks for children who wanted and needed them, noting guidance was just a recommendation and would be managed on an individual basis.

Professor Grills said the new guidance probably hadn't been made compulsory because there was very little evidence for mask-wearing in young children, "so it would be hard to justify."

The state government was asked whether the guidance was based on scientific research but didn't respond by deadline.

Professor Grills said there were better ways of managing COVID-19 risk in primary schools.

"You could have staggered play times, staggered lunch time, so you only have one class interacting at a time, which would limit potential spread."

He also argued schools should be open in areas like Warrnambool where there was little or no virus circulating.

"There really should be a graded response across Victoria. You might still have some restrictions in place in Warrnambool, but I think to have it as strict as Melbourne in terms of schools and playgrounds is unnecessary and damaging to kids."

CORONAVIRUS STORIES:

We have removed our paywall from our stories about the coronavirus. This is a rapidly changing situation and we aim to make sure our readers are as informed as possible. If you would like to support our journalists you can subscribe here.

Have you signed up to The Standard's daily newsletter and breaking news emails? You can register below and make sure you are up to date with everything that's happening in the south-west.