Australia’s sluggish vaccine rollout was last week thrown another curve ball, with new medical advice recommending under-50s be given the Pfizer jab.

Up until that moment, most Australians were slated to receive the AstraZeneca vaccine — with 53.8 million doses already secured by the federal government.

In a scramble to protect the nation, the government secured another 20 million doses of the Pfizer candidate, but these additional jabs won’t be delivered until the last quarter of this year. 

But what about Novavax?

It’s the third vaccine on Australia’s radar, and we’re expecting to receive 51 million doses this year.

But we now know the production of this vaccine has been set back due to supply shortages.

So, when exactly will Novavax arrive in Australia? And how well has it been performing in clinical trials?

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Firstly, how does Novavax work?

SARS-CoV-2, the virus which causes COVID-19 disease, has spike proteins.

Pfizer, AstraZeneca and Novavax vaccines all work by training the immune system to recognise and fight these spike proteins, but they each use different technologies to do this.

Unlike the Pfizer and AstraZenenca vaccines, the Novavax vaccine contains exactly the same spike protein as the virus.

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“It’s a more traditional way of making vaccines,” QIMR Berghofer Medical Research Institute’s Rajiv Khanna said.

Professor Khanna says to make the Novavax vaccine, the genetic sequence of the spike protein in SARS-CoV-2 is used to produce spike protein in cells in the laboratory.

The protein is then collected, concentrated, purified and mixed with other chemicals to make sure the body’s immune system mounts a strong response.

Professor Khanna says in his opinion, this approach is the “safest way of making a vaccine”.

Similar to the AstraZeneca and Pfizer vaccines, Novavax also needs two doses.

Novavax’s phase three trials

The vaccine has already been through phase three trials in the UK, showing an efficacy rate of 89.3 per cent in more than 15,000 participants.

By comparison, Pfizer is 95 per cent effective at preventing COVID-19 symptoms, while AstraZeneca’s efficacy ranges between 62 and 90 per cent (although data suggests a 12-week wait between doses could give an efficacy of about 82 per cent).

However, a separate trial of Novavax in South Africa (where the more infectious B.1.351 variant of the virus is circulating), showed the vaccine had an efficacy rate of only 49.4 per cent in 4,400 people (including HIV-positive and negative participants).

Vaccines can be less effective in people living with HIV and others who are immunocompromised and they often need extra doses of some vaccines to optimise protection.

In the South African trial, Novavax was found to have a 60 per cent efficacy rate in the HIV-negative group.

Similar to Novavax, neither Pfizer nor AstraZeneca perform as well against the South African B.1.351 variant as they do against other currently circulating variants.

Novavax’s phase three trials in the US and Mexico are ongoing, and more data about the vaccine’s efficacy rate is expected to be released soon.

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Where to next for Novavax?

Before a COVID-19 vaccine is approved by Australia’s regulator, it has to go through six phases, including evaluation.

Four different vaccines have cleared the first hurdle: Pfizer, AstraZeneca, Johnson & Johnson, and Novavax.

But only two COVID-19 vaccines in Australia have been approved by the Theraputic Goods Administration (TGA) for actual use: Pfizer and AstraZeneca. 

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Novavax has now begun its submission to Australia’s regulator, putting it at the second phase in the application process.

A spokeswoman for Novavax Inc said it would apply for approval with the UK’s regulator as early as this month, and then seek approval with the European Medicines Agency.

This means Novavax is expected to be available overseas before being approved in Australia.

Monash Institute of Pharmaceutical Sciences professor of pharmaceutical biology Colin Pouton said other countries were being offered the Novavax vaccine first because they had invested in the development of the vaccine.

“Australia is just a customer,” he said. 

“We didn’t really get involved in developing the vaccine, so we won’t get first dibs, that’s for sure.”

When will Novavax be available in Australia?

Australia has an agreement for 51 million doses of Novavax originally slated for “mid-2021”, but that target has now been pushed back until later this year.

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Before it can be offered to Australians, more positive phase three trial results are required, and then the TGA needs to review the data before authorising use of the vaccine.

A spokeswoman on behalf of Australia’s Department of Health says if these boxes are ticked, the first doses of Novavax can be expected to arrive in Australia in the third quarter of this year.

That means July, August or September — but we don’t have an exact date.

And we don’t know how many doses of the vaccine will be included in the first shipment.

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There have also been some issues sourcing key production materials to make the vaccine, including single-use bags used to grow vaccine cells.

Pfizer is facing a similar issue.

Professor Khanna is neither surprised, nor alarmed, by the reported shortages. 

“When you start producing [vaccines] at a scale of millions and millions and millions, I mean, small scale is fine, but whenever manufacturing is required at that scale, there will always be a challenge,” he said.

“Whether that be the packaging or the supply chain.”

What vaccines does the US have?

In the US, three vaccines have been authorised to prevent COVID-19 — Pfizer, Moderna and Johnson & Johnson (although the Johnson & Johnson rollout has been paused while authorities investigate a small number of rare blood blots in people who have been vaccinated).

Out of these three candidates, Australia has only struck a deal with Pfizer.

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Professor Pouton says Pfizer and Moderna show essentially the same degree of efficacy after two doses (Pfizer at 95 per cent and Moderna at 94.1 per cent) at protecting against COVID-19 symptoms.

They both use messenger RNA (mRNA) which, until recently, had not been approved for use in a human vaccine.

But why did Australia back Pfizer, but not Moderna?

Professor Pouton said the answer came down to availability — or lack thereof.

He said Moderna’s development was “substantially bankrolled by the US Government”, which meant the US had first dibs on the vaccines as they were rolled out.

Professor Khanna said the move made logistical sense.

“If you’re standing 10 people in a queue and the other queue is shorter, you always jump to the other cue,” he said. 

Although the rollout of the Johnson & Johnson has now been paused in the US, the TGA could — theoretically — still approve its use in Australia, if regulators decide the benefits of the vaccine outweighed the risks.

If this happens Australians with a prescription may still be able to get it privately, even if the government doesn’t buy it.

What’s next for Australia?

Professor Pouton said one future option for Australia was to manufacture more vaccines here.

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“It may be as time goes on, we do start making more of these vaccines in Australia for the future.”

The ABC understands Novavax has been in early-stage talks with Australia’s biopharmaceutical sector to explore options to outsource some of its supply locally.

And vaccine experts say Australia has the potential to make mRNA vaccines such as Pfizer on home soil — although it will take time and investment to ramp up domestic manufacturing capabilities.

Professor Khanna said people shouldn’t be panicking about vaccine availability in Australia, given the country’s small caseload of COVID-19 disease, unburdened hospitals, and lack of virus circulating in the community.

“I would suggest people calm down,” he said.

“We just have to keep patient … these are difficult things to manage when you have to organise vaccines for millions of people.”





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By EDONS