The coordinator of Australia's COVID-19 vaccine rollout says supplies are being "carefully managed" ahead of a major ramping up of doses from August.
Prime Minister Scott Morrison, who is quarantining at The Lodge in Canberra following an overseas trip, met via teleconference with state and territory leaders on Monday to discuss the rollout.
Premiers have been critical of a shortage of supplies.
Lieutenant General John Frewen, who is in charge of logistics for the vaccine rollout and briefed the national cabinet, told reporters the premiers had now been given a detailed breakdown of what supplies they can expect, including dose number forecasts.
"We are still in a resource-constrained environment we need to carefully manage," he said.
"But on current forecasts, we are looking forward to ramp up availability of Pfizer through August into September and into October."
The premiers were told they would get supplies based on their population proportion, which NSW Premier Gladys Berejiklian described as a "relief" to hear.
"What we highlighted today was the need for the federal government to increase the capacity of the GP network," she said.
Authorities revealed NSW's request for an additional 50,000 Pfizer doses had been approved before national cabinet.
General Frewen said it remained the plan to offer vaccines to all Australians by the end of the year.
Australian Medical Association vice-president Chris Moy said he was concerned about the rate of patients cancelling their vaccinations, after new advice about the AstraZeneca vaccine led to the cut-off age for people to receive it was lowered from 60 to 50.
The co-chair of the Australian Technical Advisory Group on Immunisation, Dr Christopher Blyth, told an inquiry hearing on Monday the benefits for people aged over 70 of getting their AstraZeneca shot far outweighed the risks.
He said the risk of over-70s dying from COVID-19 was between four and 10 per cent, while there had been two confirmed deaths from blood clots out of more than four million doses delivered.
The risk of developing a blood clot after having AstraZeneca was below two out of 100,000 in older people, 3.1 out of 100,000 for under-50s and 2.7 out of 100,000 for 50-59 year olds.
"We believe in older individuals it is clearly in favour of receiving an AstraZeneca vaccine," he said.
However, he noted his group - which provided the key advice on changing the age range for AstraZeneca - was continuing to evaluate the risks.
Therapeutic Goods Administration chief Professor John Skerritt told the hearing there were a "dozen potential conditions" on his agency's radar, ranging from blood clots to inflammation of the heart.
But no regulators around the world had directly attributed any of these other conditions to the vaccines, he said.
"It's our job as regulators is to lose a lot of sleep (and) ... as soon as there is firm evidence, provide advice."
The Senate committee looking at the rollout was told despite there being an initial meeting between health department officials and Pfizer in July last year, no formal offer was put on the table until later in the year.
"There were no numbers or details put on the table at that meeting on July 10," the vaccine task force's Lisa Schofield said.
There have now been 6.59 million vaccine doses delivered in Australia including 1.21 million in the past week.
A new advertising campaign encouraging the take up of vaccines will be launched once the team behind the supply chain is comfortable supply can meet the extra demand.
Australian Associated Press
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