More stringent lockdowns throughout the pandemic impacted the mental health of Australians more than surging case numbers, research has revealed.

While higher case numbers and deaths associated with COVID-19 impacted people's wellbeing, it was to a lesser extent than strict lockdowns.

The study's co-author Professor Nicholas Biddle from the Australian National University said it remained to be seen whether there would be a long-lasting effect as restrictions became a thing of the past.

"There is no doubt lockdowns were essential to helping stop the spread of COVID-19 and limit case numbers and potential deaths," he said.

"Our findings also show that measures designed to help protect people from COVID-19 also have a clear impact on mental health and wellbeing."

But the study found a split between the genders, with males being more severely impacted from stricter lockdowns while higher case numbers weighed heavily on females.

The study analysed the experiences of more than 6500 adults over two and a half years.

Meanwhile, health regulators are in the final stages of approving the use of the Pfizer booster shot for children aged five to 11.

The Therapeutic Goods Administration has given the booster provisional approval ahead of the Australian Technical Advisory Group n Immunisation (ATAGI) giving it the nod.

Children aged five to 11 years are currently recommended to have a primary course - two doses for most people - of a COVID-19 vaccine.

Elsewhere, Victoria will join all other jurisdictions except the ACT in doing away with mask mandates on public transport from midnight on Thursday.