Medical experts believe the federal government's coronavirus vaccination target will be hard to achieve unless jab rates are dramatically ramped up.
The Morrison government has set October as the goal for everyone who wants to receive a vaccination to have at least one dose.
Australian Medical Association president Omar Khorshid says it will be a challenge to vaccinate more than 20 million people in that time frame.
"I've been saying for a while that October is a pretty tough deadline to meet," he told the Nine Network on Monday.
Dr Khorshid said the end of the year was a more realistic target.
Infectious disease expert Sanjaya Senanayake is not concerned about the delay.
"This is going to take a long time, we talked about it being the end of October. But I suspect it will probably be by the end of the year," he told Nine.
"You want to iron out wrinkles at the start so you start off slow and build things up."
Almost 30,000 Australians had been vaccinated since last Monday, including 8110 aged care and disability residents throughout 117 care facilities.
Dr Senanayake is hopeful the rollout can ramp up to more than 150,000 vaccinations a day at its peak.
The medical regulator will begin batch testing the first doses of the AstraZeneca vaccine this week after a shipment of 30,000 landed on Sunday.
The aim is to add the vaccine to the rollout from next week, giving Australia a second shield against the disease with Pfizer jabs starting last week.
Pharmaceutical giant CSL will locally manufacture 50 million doses of the AstraZeneca vaccine, which most Australians will receive.
The government has kicked off a second $31 million public information campaign on the vaccination program.
Health Minister Greg Hunt said a myth-busting unit has also been set up to stamp out "plainly ridiculous" information like 5G theories.
"We don't want to give too much air to some of the silliest ideas," he said.
"But we do want to provide public reassurance to combat in the marketplace those ideas which would in any way falsely have some impact on public confidence."
Australia's national medical authorities have officially labelled Auckland as a hot spot after the New Zealand capital was placed under a snap one-week lockdown.
People from the rest of New Zealand can continue to fly to Australia without the need for a 14-day quarantine.
Australian Associated Press