A virologist says that with COVID-19 mutating at an "extraordinary rate", it is vital Australia starts to make its own mRNA vaccines - like Pfizer - onshore.
Growing caution and concerns about the AstraZeneca vaccine's link to a "very rare" blood clotting syndrome continue to plague the already lagging vaccine rollout in Australia.
But Associate Professor Nathan Bartlett, based in NSW's Hunter Valley, said that while AstraZeneca still had an important role to play in the country's response to the pandemic, mRNA vaccines - such as Pfizer's- should eventually take its place.
The HMRI and University of Newcastle researcher said the advantage of mRNA vaccines was they were much easier to update than the "viral vector" vaccines like AstraZeneca's - the effectiveness of which would likely erode over time.
"This virus is mutating at an extraordinary rate, creating a plethora of variants that have variable susceptibility to the vaccine," he said.
"The situation could be that a variant of concern in India or South Africa will be different to the one threatening us. So the ability to tailor our vaccine to quickly start immunising against the virus most impacting our country is going to be key.
"The only way you're going to be able to do that is to have the capability to make those vaccines ourselves - at scale - and get them distributed efficiently. We need to generate capability in Australia to make our own mRNA vaccines so we have no issues with supply and we tailor them to deal with the particular variant threatening us."
This virus is mutating at an extraordinary rate, creating a plethora of variants that have variable susceptibility to the vaccine.Associate Professor Nathan Bartlett
Associate Professor Bartlett said at the beginning of the pandemic, the AstraZeneca vaccine was "clearly our best option".
"On paper, at that point, that was the one to go for," he said. "We could guarantee we could make it, we could guarantee that we could distribute it, it didn't require the same level of cold storage, and we had a good understanding of how it worked. The mRNA was a new technology, so there was a lot of unknowns.
"Fast forward some 12 months and a lot has happened, and a lot has changed.
"Now we've had rollout in the real world where we're not talking tens of thousands of people, we're talking hundreds of thousands to millions of people who have been vaccinated - and with those numbers it has revealed very low rates of these adverse events associated with adenovirus-based vaccines like AstraZeneca."
Associate Professor Bartlett said it was believed the link was caused by an immune response which attacked blood cells leading to the clots and low platelet counts seen in around 1 in 250,000 people vaccinated with the AstraZeneca shot.
But while so few Australians currently had immunity to the virus, we remained vulnerable to outbreaks.
It meant that should the virus reappear now, we would have to rely on lockdowns, masks and other strategies again.
"This country has zero immunity. So if an outbreak did occur it would tear through the population very, very quickly and cause significant illness and some death," he said. "It only takes one mistake or one outbreak and we could have a serious problem. Right now, the AstraZeneca vaccine still has a role in Australia's current vaccine strategy.
"We have it and we can make more of it, so let's get it out there for over-50s as well as give those under 50 the opportunity to make an informed choice to have this vaccine. But long term, I don't think these viral vector vaccines are going to be useful."
It comes as Australian health workers and academics added their signatures to an open letter to Prime Minister Scott Morrison, urging him to support a temporary waiver of intellectual property rights for life-saving vaccines to make them more accessible globally.