The extension of Sydney's lockdown has yet to be confirmed but will almost certainly run into August, with NSW reporting 172 new COVID-19 cases on Tuesday.

NSW Premier Gladys Berejiklian has made it easier to get an AstraZeneca jab via pharmacies and state hubs, while Pfizer vaccine supplies remain tight.

With at least 79 of the latest NSW cases active in the community for all or part of their infectious period, and two unvaccinated women dying on Monday, Ms Berejiklian appealed for people to stick to the restrictions and get vaccinated.

"If you think you're immortal, if somehow you think you're special and you're not going to get the virus - your parents, your sisters, your brothers, your loved ones may not be in that category."

It's better news for Victorians and South Australians.

Both states are coming out of lockdown from Wednesday morning after bringing respective outbreaks of the Delta variant under control.

A leading epidemiologist says prioritising under-40s for vaccinations is key to ending the stop-start cycle of lockdowns and border closures.

Mary-Louise McLaws also wants Pfizer doses funnelled into NSW and Victoria, which together represent 58 per cent of Australia's infections to date.

"If we actually go to hotspots, such as Victoria and NSW, and dampen down that risk by focusing on the 20 to 39 year olds who have had most infection, then the rest of the states and territories around Australia won't have to suffer," Professor McLaws said.

"I know it feels unfair. But from an epidemiological perspective, you go where you're going to get most of your results."

Frontline supermarket and warehouse workers in Sydney hotspot areas will be given priority access to Pfizer doses.

Pfizer gives under-40s the greatest protection from symptomatic infection and remains the preferred vaccine for people under the age of 60.

But all adults in Sydney are strongly recommended by the nation's immunisation advisory panel to consider AstraZeneca.

The rapidly changing advice and low risk of rare blot clots has fed into hesitancy about AstraZeneca, while Pfizer supplies remain tight.

Professor McLaws also wants to see real-time testing of people without symptoms at essential workplaces.

With Sydney's lockdown scheduled to end on Friday, Ms Berejiklian promised to detail her government's plans on Wednesday.

Prime Minister Scott Morrison and state and territory leaders are expected to receive vaccine coverage modelling on Friday which will allow a staged end to rolling lockdowns and border closures.

Victorian Chief Health Officer Brett Sutton, whose state recorded 10 new local cases on Tuesday, suggested more than 80 per cent of Australians would need to be vaccinated to achieve herd immunity.

The Queensland government is reconsidering its travel rules regarding Victoria and SA.

Just over 16 per cent of Australians over the age of 16 are fully vaccinated.

Australian Associated Press