A new COVID sub-variant circulating in Australia is not yet causing concern among health experts, says the deputy chief medical officer.

Professor Michael Kidd says although the Omicron sub-variant - known as BA.2 - appears to have a higher "growth advantage", which means it could be more contagious than the original variant.

But he says it is not yet known whether it is more severe.

"We are not picking up anything that is causing concern at the moment," he told reporters in Canberra on Monday.

Australian Epidemiology Association president Brigid Lynch says global health organisations were treating the new sub-variant as a "watch and wait" situation.

Professor Lynch said it was important to determine whether it causes more severe illness, which would take time.

"There is no credible information suggesting the new variant evades vaccine protection or causes more severe disease," she told AAP on Monday.

A more contagious variant could cause another wave of infections and people should keep taking the same precautions like getting vaccinated and boosted, wearing masks and physically distancing, Professor Lynch said.

The Omicron sub-variant was first detected in southern Africa and is quickly becoming the dominant strain in a number of countries.

It was first detected in Australia in December last year in a Queensland patient.