More than six million Australians are now eligible to receive coronavirus vaccines under a new phase of the national rollout.

Phase 1b of the program kicks off across the country on Monday.

Everyone over the age of 70 is included in the stage, along with Indigenous Australians over 55 and younger adults with a medical condition or disability.

Workers deemed critical or high risk can also apply to receive jabs.

Deputy Chief Medical Office Michael Kidd said it was an incredibly important milestone in the country's fight against COVID-19.

"If you are eligible to get the vaccine, as one of those six million people, please make sure you do so over the coming few months," he told the ABC.

The initial phase of the rollout will continue for another six to eight weeks until all people in that group have received their second jab.

More than 1000 general practices have registered to administer the vaccine, with another 3500 clinics to begin over the next four weeks.

Vaccines will also be available at 100 respiratory clinics.

Flooding has caused delays across some parts of NSW.

Emergency Management Minister David Littleproud said the length of the interruption would depend on how quickly floodwaters abated.

"We're in no rush, we're in a really good position in Australia, better than any other country in the world because we've been able to manage this pandemic," he told Sky News.

"We haven't got people severely ill in hospitals in any great quantities.

"We're very confident that we'll work with the medical profession to roll those vaccines out in a COVID-safe way and a safe way in terms of emergencies, once the water abates."

The government appears to be adopting a "don't call us, we'll call you" approach to the vaccine rollout.

General practices will be contacting their patients most at risk, including very elderly people.

People can also go online to find out whether they are eligible and where the vaccine is being delivered in their local area.

"Please be patient but when you get a chance, make your booking and roll up to get your shot," Professor Kidd said.

Regulators have finalised approval for the locally manufactured AstraZeneca jab, with the first doses expected within days.

The federal government will not say how many doses CSL will produce in its first few weeks or when the rollout will ramp up to the promised one million doses a week.

People are also being reminded to have their annual flu shot, which will become available over the coming month.

A 14-day gap is recommended between receiving the COVID and influenza vaccines.