Leaders in NSW and Queensland have poured cold water on Prime Minister Scott Morrison’s suggestion that “vaccine passports” could help ease state-based coronavirus restrictions for fully vaccinated Australians.

Mr Morrison stressed the states are “the ones who put those restrictions [on interstate travel] on, under their public health orders”.

However NSW Premier Gladys Berejiklian told The Australian vaccinations should only be deployed to reopen the international border.

“There should be no internal borders. There should be free movement within Australia, vaccine or no vaccine,” she said.

Ms Berejiklian’s opposition to the plan has been echoed by other members of Parliament.

Queensland Premier Annastacia Palaszczuk has labelled the idea a ‘thought bubble’.

The Prime Minister remains enthusiastic about the proposal.

“The virus is raging around the world and it’s now ravaging the developing world. That is likely to see more strains, more variants, come through, so we have to be exceptionally cautious,” Mr Morrison told Melbourne radio station 3AW radio.

“That’s why the borders remain closed, and that’s why we look to further liberalise things that are safe.”

He said that if a person was fully vaccinated and the state government decided to close the state border, a vaccination passport might mean “you … are able not to be subject to those restrictions”.

“That’s something I’m happy to talk through with the states because ultimately they’re the ones who put those restrictions on.”

• Vaccinated people could avoid lockdowns, in ‘vaccine passport’ plan

The Australian government is understood to be in talks with the International Air Transport Association about a new digital certificate that could unlock quarantine-free overseas travel for vaccinated Australians.

A recent poll suggested almost three-quarters of Australians would back a COVID-19 vaccine passport.

Mr Morrison has meanwhile downplayed the need to counter vaccine hesitancy through a revamped campaign.

The Australian Medical Association wants a more effective national strategy to motivate people who are in no rush to get their shots.

AMA deputy president Chris Moy has warned Australians are sitting ducks until enough people are inoculated.

He wants to convince people to roll up their sleeves by promoting the benefits.

“At the moment, given we have no COVID and we are living in this really gilded cage, people do not perceive a risk,” Dr Moy told ABC radio on Thursday.

“Seeing for example what is happening overseas where there is a tsunami of COVID and also the development of variants, we are sitting ducks until we get a significant proportion of the population vaccinated.”

The Prime Minister said the government was already running a multi-million dollar advertising campaign to encourage vaccine uptake, targeting priority groups including older adults and aged care residents.

Mr Morrison argued the campaign would ramp up later this year as big shipments of Pfizer vaccines arrived and more people became eligible.

“There’s no point talking to people who are 30 years old at the moment, because they can’t go and get a vaccine,” he told 3AW radio.

“We’re talking to those who are eligible for the vaccine at the moment, which is over 50s and particularly those who are over 70 and in residential aged care facilities.”

Health Minister Greg Hunt said everyone aged over 50 should get vaccinated as soon as possible.

But he also raised eyebrows after reminding those uncertain about the AstraZeneca jab that alternative vaccines would soon arrive.

“We want to encourage everybody over 50 to be vaccinated as early as possible,” Mr Hunt said.

-with AAP