Australia is expected to follow other parts of the world in expanding eligibility for a fourth COVID vaccine dose to the wider population.

It comes as virus cases surge across Australia and health authorities urge people to wear masks, while some states are also considering more virus rules.

Prime Minister Anthony Albanese said immunisation experts would look at available evidence before making a recommendation.

“The pandemic isn’t over, so my view is that [Australia] will inevitably follow what has occurred in other parts of the world and roll out a further booster shot,” he said in Sydney on Wednesday.

“I’d encourage people who haven’t had their booster shots to go out there if they’re eligible and do it as a matter of urgency.”

The Australian Technical Advisory Group on Immunisation is expected to discuss the benefits of expanding the fourth dose eligibility at its meeting on Wednesday.

It is currently available for Australians over-65 years and vulnerable people.

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Elsewhere, South Australian authorities said they could not rule out reintroducing restrictions, with COVID cases expected to rise in coming weeks, as the new subvariants BA.4 and BA.5 take hold.

Modelling released for SA on Tuesday showed case numbers were expected to peak in about three weeks at 5000-6000 a day, about about 1000 more than previous estimate..

Chief public health officer Nicola Spurrier said the modelling was the “least certain we’ve been because we don’t have a lot to go on” but she believed numbers would rise as forecast.

Meanwhile, Queensland’s chief health officer John Gerrard has recommended that older people and those who are immunocompromised should wear masks in crowded places until at least the end of August.

Queenslanders are being urged to prepare for the state’s third COVID-19 wave with hundreds of people already in hospital.

Dr Gerrard said the peak would come at the end of July or early August, or later, and place even greater pressure on hospitals.

“These subvariants can evade immunity whether that be acquired through vaccination or natural infection,” he said.

“It’s very likely that either you or someone you know close to you will be infected, it will be very common, so my message is it’s important to for you to prepare now, I’ll say that again: It is important for you to prepare now.”

The call was echoed by Tasmanian Premier Jeremy Rockliff, who has strongly recommended people wear masks indoors.

It followed NSW chief health officer Kerry Chant urging people to consider wearing masks in enclosed spaces to curb the spread of disease in NSW.

NSW Health Minister Brad Hazzard also warned that anyone who wasn’t fully vaccinated was “crazy” as his state braced for a third wave to peak in late July and early August.

Australia’s latest COVID vaccine booster rates. Image: Federal government

On Tuesday, Victoria extended its pandemic declaration by three months. The declaration was due to expire before midnight on July 12, but has been extended until at least October 12.

Premier Daniel Andrews said he was satisfied COVID-19 continued to pose a “serious risk” to public health throughout the state, which justified ongoing public health measures over winter to reduce the risk of transmission and hospitalisation.

As Victoria’s death toll rose above 4000, Mr Andrews said he couldn’t make it any clearer that vaccines worked. However, he stopped short of telling Victorians to don masks outside mandated settings such as health facilities, aged care and public transport.

More than 43,500 COVID infections were reported nationally on Wednesday, and experts warn case numbers will climb even further as winter progresses.

There were also 3780 people with COVID in hospitals across the country. That is the highest level since February, at the height of the Omicron wave.

The surge in cases is being driven by two Omicron subvariants, BA.4 and BA.5.

International arrivals no longer need to declare their vaccination status to enter the country.

Australia’s latest 24-hour COVID data

Victoria: 10,056 cases, 23 deaths, 523 in hospital with 29 in ICU

NSW: 13,775 cases, 10 deaths, 1822 in hospital with 64 in ICU

Tasmania: 1700 cases, one death, 79 in hospital with two in ICU

Queensland: 5878 cases, four deaths, 705 in hospital with 18 in ICU

ACT: 1477 cases, no deaths, 135 in hospital with five in ICU

Western Australia: 6296 cases, one death, 226 in hospital with eight in ICU

South Australia: 4072 cases, five deaths, 267 in hospital with 11 in ICU

Northern Territory: 342 cases, no deaths, 24 in hospital with one in ICU

-with AAP