The federal government hasn't received any advice on retightening COVID-19 mandates, Prime Minister Anthony Albanese says, as evasive new Omicron variants fuel a rise in cases.

More than 37,000 new infections and 77 deaths were reported across Australia on Saturday as BA.4 and BA.5 overtake BA.2 as the dominant strains.

Almost 42,000 cases and 35 fatalities were announced nationally on Friday, the third 40,000-plus day in a row.

The number of Australians hospitalised with the virus tops 4000, up by more than 1000 in the past fortnight.

Mr Albanese says restrictions, if they need to be reviewed or reintroduced, will be examined by individual states and territories.

However, the federal government on Monday will move forward on the issue of access to vaccines.

"It's recommended that those above the age of 50 do get their additional booster shot," he told reporters in Canberra on Saturday.

"I aim myself to get an additional booster. People, if they are eligible, should do that. It minimises the impact and people should follow that health advice. People of the age of 30 and above as well, they are eligible.

"The pandemic isn't over."

From Monday, Australians over 30 will be able to get a fourth vaccine dose, or second booster.

Deakin University epidemiology chair Catherine Bennett said it was difficult to determine how transmissible the new Omicron variants were due to waning vaccine immunity and differing levels of prior infection.

They made everyone fair game for infection or reinfection but hospitalisations were unlikely to reach levels seen during the initial Omicron wave, she said.

Preliminary research from Japan indicates the variants could replicate more efficiently in the lungs than BA.2, and Prof Bennett said this could lead to an increase in lower respiratory tract and secondary infections.

"It's not like saying that's going to increase our death rate but it could as secondary infections become harder to manage," she said.

Increasing cases have led to calls from some to reintroduce indoor mask mandates in an attempt to curb transmission.

However, Prof Bennett said she didn't believe compulsory mask-wearing should be reintroduced and instead wanted authorities to re-engage with the COVID-fatigued community with targeted public health messages.

LATEST 24-HOUR COVID-19 DATA:

NSW: 11,434 cases, 33 deaths, 1894 in hospital with 61 in ICU

Victoria: 8776 cases, 20 deaths, 667 in hospital with 34 in ICU

Queensland: 5315 cases, eight deaths, 719 in hospital with 15 in ICU

SA: 3246 cases, four deaths, 245 in hospital, eight in ICU

WA: 5538 cases, 11 deaths, 252 in hospital, eight in ICU

Tasmania: 1511 cases, no deaths, 89 in hospital, two in ICU

ACT: 1120 cases, one death, 138 in hospital, five inICU

NT: 354 cases, no deaths, 20 in hospital, one in ICU