Mass vaccination is the way to counter emerging coronavirus variants, including those seen in Melbourne's outbreak, says Chief Nursing Officer Alison McMillan.

Australia's chief nurse has declared mass vaccination will be the key to defeating mutant coronavirus strains, including variants detected in the Melbourne outbreak.

The Victorian outbreak has infected 85 people with the Delta and Kappa strains which caused havoc when they spread rapidly in India.

Chief Nursing Officer Alison McMillan said vaccination would be the only way to counter emerging variants.

"There are multiple strains and we will continue to see COVID adapt and mutate - that's what these viruses do," she told Sky News on Tuesday.

"We're likely to see other strains emerging. The sooner we can get the world vaccinated, the less likely it is that it can mutate.

"It mutates and finds it easier to do when there's a significant population infected at any one time."

The sluggish national rollout of jabs continues to spark concern with Melbourne in the grips of another lockdown, which is due to ease on Friday.

While the immunisation program is ramping up, just 613,000 people, or about 2.9 per cent of the nation's adults, have received both doses.

Professor McMillan is confident that figure will grow significantly with many people nearing the end of the 12-week gap between AstraZeneca shots.

Victoria's Chief Health Officer Brett Sutton tweeted on Tuesday his state was on track to vaccinate one million Victorians every three weeks, and possibly four million from now until the end of August.

"What a difference that would make to protect us all," he said.

More than 5.2 million doses have been administered nationwide including more than one million over the past 10 days.

With the federal government under sustained pressure over the pace of the rollout, more categories of Australians have been added to the eligibility list.

National Disability Insurance Scheme participants aged over 16 have been included in the program, which last week was opened to all Aboriginal and Torres Strait Islander people.

All Australians over 40 are now eligible for a jab, while the Northern Territory has become the first jurisdiction to offer all of its citizens a chance to be immunised.

Prime Minister Scott Morrison noted there were thousands of positive cases each day in major developed countries where vaccine rates have been high.

Mr Morrison said Australia was in a rare position of having a stronger economy than before the pandemic hit.

"That will continue so long as we get the balance of risk right in our judgments when it comes to any lockdowns," he told reporters in Sydney.

"It must be proportionate. It must be targeted. It must be temporary."

He stopped short of criticising the Victorian government over the lockdown but reiterated restrictions should ease as soon as possible.

The latest Essential poll has detected an increasing number of voters disappointed with federal and Victorian government responses to the pandemic.

Based on the survey of 1104 Australians, almost a quarter of people believe the Morrison government's handling has been poor - the highest figure since the pandemic begun.

Among Victorians, both governments suffered a 15 percentage point drop in support for their COVID-19 response.

Just 42 per cent of those said the federal coalition's actions were good, lower than the 48 per cent who thought the same about state Labor's response.