Prime Minister Scott Morrison says every Australian will have access to the coronavirus vaccine by Christmas.
However he added higher vaccination rates won't necessarily stop lockdowns.
"We have caught up a lot of ground on this program and Australians are responding really well. We need that to continue not just in NSW but right around the country," Mr Morrison told Today.
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"That's why I think the boosting of the AstraZeneca vaccine, the new advice from the immunisation advisory body is very important. It's a strong vaccine. It's an effective vaccine.
"It's the most recognised COVID-19 vaccine in the world and it saved millions of lives. And it can do the same here in NSW and across the country.
"So lifting those AstraZeneca vaccine rates in NSW will be incredibly helpful.
"(Vaccines) will certainly help the efforts with the lockdown. But on its own it won't stop the lockdown."
The Prime Minister said authorities and the community "have to make sure this lockdown is effective" as Sydney begins another four weeks of stay at home orders.
"I can't guarantee there won't be more lockdowns," Mr Morrison said.
"The Delta variant is the one that is most punishing here. The lesson of the last six weeks or so is that, under the Delta strain, going quickly and early is the new mode of operation."
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Mr Morrison has also defended the delayed rollout of a financial support package to help struggling businesses affected by COVID-19 lockdowns.
"$400 million and more already in people's bank accounts, giving support to more than 400,000 people across NSW," Mr Morrison said.
He said the money would keep flowing "as long as the lockdown goes".
But he's admitted to being worried about a prediction from the major banks that 300,000 people across Sydney could lose their jobs in the next month.
"Of course I am (worried) and that's why we have put the support payments in to help people to get through this.
"Of course there will be (an) impact. But there is this hope.
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"I expect that we'll see the NSW economy turn around quickly provided – and that's why these payments are so important because they keep those businesses as whole as possible so, when the restrictions lift, they can get back to work and the jobs can come back.
"Yes, there is that risk. But there is also the hope that the economy turns around very quickly and we are not seeing that big rise in JobSeeker applications because our disaster payments are working."
