Expanding eligibility for a fourth COVID-19 jab could leave those most vulnerable to the virus, including the elderly, behind in the broader vaccine rollout, a leading expert has warned.

The Australian Technical Advisory Group on Immunisation met on Wednesday to discuss the possibility of expanding access for a fourth vaccine dose - or second booster - to the broader population following a rise in infections.

Currently, the fourth dose is only available to those over 65, people in aged or disability care and the immunocompromised.

But Australia's immunisation experts could recommend that be expanded to anyone over the age of 50, and allow anyone over 30 to have another booster if they wish.

A decision is not expected until at least Friday, according to Health Minister Mark Butler.

However, Australian National University infectious diseases expert Professor Peter Collignon said those who were more vulnerable to the virus should still be prioritised for a fourth dose.

"By looking at everybody for this, we're missing the people who are most at risk," he told Sky News on Thursday,

"By doing the whole population as we're doing, and implying almost everybody's equal, we're missing the people who are dying the most, and that's those who are older."

ATAGI had delayed recommending a fourth shot until a fresh wave of infections threatened, Australian Medical Association vice-president Chris Moy said.

"(ATAGI has) been under pressure for a long time now to go to the fourth shot for everybody," Dr Moy told ABC radio on Thursday.

"We're facing a new surge, a really worrying surge ... we are looking at hospitals which are already full facing a real disaster in terms of being overrun, so this is why I think the decision is coming."

Mr Butler has warned Australia is in the early stages of a fresh wave of COVID-19.

"Case numbers are rising, hospitalisations are up by several hundred just in the fortnight, and most state governments and the federal government are projecting that that's going to continue for some time yet," he said in Adelaide.

Prof Collignon said with rising cases across the country, reinfection would be a bigger risk.

"Until we get new vaccines that are better at stopping that, we have to accept that we're likely to get second infections," he said.

"But it will be much less severe in general and have less consequences than that first infection."

Meanwhile, young people have had the largest drop in life satisfaction since the start of the pandemic, according to a study.

The Australian National University's COVID-19 Impact Monitoring survey found those aged 18 to 24 had experienced a significant reduction in life satisfaction since the beginning of 2020.

Their average life satisfaction rating fell by 0.5 to sit at 6.3 points out of a possible 10.

The survey of more than 3500 people assessed how the pandemic affected their lives and also found men and women had experienced a similar drop in life satisfaction since the pandemic began.

But those over 55 were less likely to suffer a drop compared with those under 55.

LATEST 24-HOUR COVID-19 DATA:

NSW: 13,343 cases, 22 deaths, 1822 in hospital with 62 in ICU

Victoria: 10,265 cases, 12 deaths, 592 in hospital with 30 in ICU

Tasmania: 1728 cases, no deaths, 80 in hospital with three in ICU

NT: 353 cases, no deaths, 19 in hospital with none in ICU

WA: 6387 cases, eight deaths, 240 in hospital with 12 in ICU.