Chief medical officer Paul Kelly has defended Australia's approach to COVID-19 vaccination, saying the government's approach will allow more Australians to be vaccinated quickly.
Professor Kelly threw his support behind the vaccine candidate under development by multinational company AstraZeneca, after media reports that questioned its ability to provide herd immunity.
Most Australians are likely to be vaccinated using the AstraZeneca vaccine, which the government has ordered 53.8 million doses of, the bulk of which will be manufactured in Australia by pharmaceutical company CSL.
On Wednesday Nine newspapers reported the Australian and New Zealand Society for Immunology and Australasian Virology Society had called for the rollout of the AstraZeneca vaccine to be paused, due to early data showing a 62 per cent efficacy rate against the virus.
Since then, both organisations have backed away from the call, but other experts have said the AstraZeneca vaccine is unlikely to achieve herd immunity.
Australia has also signed up for 10 million doses of the vaccine developed by American company Pfizer, showing up to 90 per cent efficacy against COVID-19. It is likely to be used for early rollout to healthcare workers and priority groups, but it can't be manufactured locally.
The Therapeutic Goods Administration is in the final stages of assessing and approving both vaccines, with early data from clinical trials pointing towards immune responses that stop a recipient getting sick from COVID-19, but experts say we must wait longer for evidence that either of the vaccines prevent a vaccinated person from transmitting the virus to others.
Professor Kelly blitzed media on Wednesday to reject the call to pause the rollout and quash fears Australians weren't going to get the best vaccine on offer.
"The choice is not whether one is better that then other, it's which one is available to give the maximum rollout of vaccine to save lives and to protect lives this year," Professor Kelly said.
"All of the three vaccines that have so far published their data in peer reviewed journals, that's AstraZeneca, Pfizer and Moderna, all show a very significant effect against severe illness. They're all good at protecting against severe illness and death.
"That's why I say that lives will be saved by the AstraZeneca vaccine, I have no doubt about it."
The Australasian Society for Infectious Diseases, the Australasian College for Infection Prevention and Control and the Public Health Association of Australia put out a joint statement on Wednesday supporting the government's COVID-19 vaccination strategy, and both vaccines had exceeded the standard set by international regulators for efficacy.
"Furthermore, no vaccines to date have been shown to prevent transmission of virus and we don't yet know how long immunity will last with the different vaccine candidates," the statement said.
Asked why Australia had not ordered more doses of the Pfizer vaccine, Professor Kelly said that number had been reached in negotiations as it was what the company said it could provide to Australia in the first half of this year, but the government was in ongoing talks with the company.
"If there were more doses available to us then we would look into whether that was a feasible option for us to get more. So far that's not the case."
The government is limited in its ability to order more Pfizer vaccines as there is no capability to manufacture the mRNA technology here, with the COVID-19 vaccine the first to be using the method. While developing the capability was considered by the government, it wasn't believed to provide the quickest way to vaccinate the population.
Professor Kelly said he was concerned the current debate could have a negative effect on confidence in the vaccines for COVID-19.
"I am worried, and worried about the selective use of the data that we have, those interim results from particular studies back in November," he said.
"And just to absolutely put it on the table today, that the TGA will go through all of the things they need to do, all of the usual checks and balances, and it's only when they have finished that full approval process that the - any vaccine will be available in Australia, including the AstraZeneca and if Pfizer vaccines."
Professor Julie Leask, expert in vaccine hesitancy at the University of Sydney's School of Public Health said the debate had the ability to undermine public confidence in vaccines, even though it isn't about safety.
"The concern I have is a lot of the public won't see the nuance in this discussion and assume that inferior also means somehow unsafe as well, and while that's not the case, the perception could lead to fewer people having the AstraZeneca vaccine when it's offered to them."
While Professor Leask said it was important to have freedom of speech and for concerns to be raised, it was a big step to call for a government rollout to be paused based on interim data.
"As a social scientist specialising in immunisation, I'm very concerned a premature call for a major policy change without full evidence could unreasonably undermine confidence in a vaccine and cause lower coverage."
She called on the government to accelerate the rollout of its vaccination communication campaign, which is set to cost $24 million and be aimed at groups with specific fears about the vaccine.
Professor Leask said such statements from scientists and doctors would have more effect on people who were hesitant around taking the vaccine than comments by government backbencher Craig Kelly, who has espoused many conspiracy theories related to COVID-19.
Associate Professor Holly Seale, whose expertise is in perceptions and behaviours regarding infectious diseases, including immunisation, says the government needs to communicate quickly, and transparently about the vaccines.
"We can see that there are questions and concerns amongst members of the public and also among healthcare providers," she told The Canberra Times.
"We've got to be ensuring information is available about the vaccine and about the process of how it was developed and safety information that is available, and up to date and also information that continues to be updated using dashboards to document adverse events if they happen."