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Australia has to meet Australians鈥� growing demand for COVID-19 vaccinations.

Australia has been , but this vaccine is no longer recommended for those aged under 60 because of the small but serious risk of clotting.

Now a research team at Monash University, led by , hopes to develop a new mRNA vaccine, which works by the same principles as the Pfizer vaccine, and could be manufactured locally.

So how would the vaccine work? What hurdles do the researchers need to overcome to make it a reality? And when could it become available?

It鈥檚 based on existing technology

Before COVID, the researchers were developing mRNA vaccines against a variety of viruses and diseases, and testing the technology in mice. After the pandemic hit, they pivoted their skills and technology and started work on an mRNA vaccine against COVID-19.

The vaccine is an mRNA vaccine, like the ones by and . These vaccines prompt your body to produce the virus鈥� spike protein, to which your immune system makes antibodies against.

But the Monash mRNA vaccine is a little bit different, as it directs our cells to only make a , the 鈥溾��, which is the most important part allowing the virus to enter our cells.

The receptor binding domain, or , is also the part that鈥檚 quickly mutating to form the different variants of concern. Directly targeting this part makes sense to get the most variant-specific response.

How do mRNA vaccines work again?

MRNA vaccines work as instructions, telling our cells to make certain proteins. If these proteins are foreign to our bodies, our immune system will recognise them and mount an immune response. Over time, immune memory is developed, meaning when we encounter the virus, our immune system will clear it.

The researchers began modelling the vaccine off the original strain of the virus, first discovered in Wuhan. But they鈥檝e since adjusted their sequence to model the shot off the Beta variant, first discovered in South Africa. This adjustment was made partly because the neutralising antibodies from patients infected with the Wuhan strain .

Our current crop of approved COVID vaccines protect well against the Alpha variant, first found in the United Kingdom, and the Delta variant, first discovered in India. But because the Beta variant is good at evading immunity from vaccines, it鈥檚 more likely than most other variants to surge when vaccine protection begins to wane.

For these reasons, there鈥檚 a stronger clinical need for Beta variant vaccines.

This quick adjustment of the sequence demonstrates how flexible the mRNA technology is. It鈥檚 easy to change the sequence of the vaccine to adapt to new variants of the virus that have emerged, and might emerge in future. This ability to quickly change the sequence is similar for DNA vaccines like AstraZeneca, but harder for traditional and protein-based vaccines.

As with all other mRNA vaccines, the RNA will be broken down in the body over the course of a day or so. The vaccine doesn鈥檛 stay in your body over the long term. You gain immunity as your immune system learns how to respond to the short burst of proteins your body makes. When you get the second dose of mRNA vaccine, the immune memory is reinforced.

The group has tested this vaccine in mice, and says its results are really promising.

Based on these pre-clinical results, the Victorian government has given the project A$5 million. The money has come out of a earmarked to support local mRNA vaccine development.

The A$5 million will help pay for a manufacturer in Europe to make a sufficient amount of the mRNA for the phase 1 trials. This material will then be shipped via ultra-cold storage to Australia, and a local company is going to package the RNA into 鈥渓ipid nanoparticles鈥� which allows the mRNA to get into human cells.

What are the next steps?

Phase 1 trials to check the vaccine is safe in humans will begin in , and will initially include 150 volunteers.

If the vaccine passes this trial, it will move to phase 2 and 3 trials which require tens of thousands of participants. The primary aim of these later stage trials will be to see if the vaccine can reduce the severity of COVID-19 disease, while also checking it鈥檚 still safe.

These later stage trials are quicker to complete if conducted in areas with (unfortunately) high community transmission. One reason we saw Pfizer and Moderna鈥檚 vaccines approved so quickly was because trials took place in countries where the virus was rampant. If and when this vaccine goes to phase 2 and 3 trials, Australia will hopefully not be in a situation with widespread transmission. So the team may need to involve international partners and recruit participants overseas.

However, there may also be alternative metrics to measure how well a vaccine is working. Researchers can look at study volunteers鈥� blood to see how many, and the type of, antibodies they鈥檙e producing. This could work as a proxy for measuring efficacy. But it鈥檚 not clear if Australia鈥檚 drug regulator, the Therapeutic Goods Administration, would approve the vaccine without the traditional exposure model.

The team will also compare their mRNA vaccine directly with Pfizer, in a side-by-side comparison, to see how stable it is and how well it elicits antibodies against the virus.

So when can we get it into our arms? It鈥檚 uncertain how long the full suite of trials will take, but probably not for a couple of years. It鈥檚 possible the vaccine will not make it past phase 1 or 2 trials, although with the similarity in methodology to the Pfizer and Moderna vaccines, both of which are safe, this is less likely.

Why we need Australian-made vaccines

This is an important step in developing Australia鈥檚 sovereign capacity for mRNA vaccine production, and for the . It鈥檚 likely we鈥檒l need booster shots for some years to come, so we need to develop local manufacturing capability.

I sincerely hope it鈥檚 successful, but even if it鈥檚 not, it鈥檚 creating a pipeline for onshore mRNA vaccine development.

What鈥檚 more, mRNA vaccines are the new gold standard and the next generation vaccine technology. It鈥檚 likely we鈥檒l see more pandemics and novel viruses in future, so that adds to the argument for having local mRNA vaccine capacity.

We don鈥檛 know how much the federal government paid for the Pfizer and Moderna vaccines, but it鈥檚 likely to have been much more costly than making it here. If we can make it ourselves more cheaply, we鈥檙e at a real advantage.

This article is republished from under a Creative Commons license. Read the .

Image credit: 漏stock.adobe.com/au/thodonal

Originally published