The long-awaited rollout of Australia's first protein-based COVID-19 vaccine is officially underway.
On Monday, Novavax joined the national vaccine program — a week earlier than expected — following the arrival of the first batches of the vaccine in Australia last week.
The Novavax jab, which was approved by the Therapeutic Goods Administration (TGA) in January, is available at GP clinics, community pharmacies and state-run vaccine hubs.
Almost 95 per cent of Australians aged 16 and older have received two doses of a COVID-19 vaccine, but the federal government hopes the introduction of Novavax will encourage those holding out to finally come forward.
"Despite high vaccination rates in Australia, there has been a demand for a protein-based formula," Health Minister Greg Hunt said.
Who is eligible for Novavax?
The Australian Technical Advisory Group on Immunisation (ATAGI) recommends Novavax for people aged 18 years and older.
It is available to be used as a first and second dose — to be given at least three weeks apart — but at this stage isn't recommended as a booster (more on that later).
The government says part of the reason it has made Novavax available is to offer more choice to people who are yet to be vaccinated.
"For some who may have had contraindications or reactions with regards to other vaccines, this will provide an additional opportunity for them, as well as those who, for whatever reason, have not taken up the program so far," Mr Hunt said after the vaccine received final ATAGI approval.
MRNA vaccines like Pfizer and Moderna and viral vector vaccines such as the AstraZeneca shot have been shown to be safe and effective at protecting people against COVID-19.
But TGA head John Skerritt, speaking when Australia's drug regulator approved Novavax, said he was aware of a small section of the community who had been hesitant about existing coronavirus vaccines and expressed a preference for the Novavax formula.
"There are some individuals who have been waiting for Novavax and it's great that it's finally been approved," he said.
How does Novavax work?
Like other COVID-19 vaccines, the idea behind the Novavax jab is to expose your immune system to the spike protein found on SARS-CoV-2, so that your body learns to recognise the virus and fight it.
But unlike mRNA and viral vector vaccines, which contain genetic material telling your body how to make the spike protein, the Novavax vaccine contains the actual spike protein itself.
"With the mRNA vaccines like Pfizer and Moderna, we inject the [genetic] instruction to make the spike protein," infectious diseases physician Paul Griffin told ABC News Radio.
"With AZ, we put those same instructions in a harmless virus and deliver them where they need to go.
"But with Novavax, it's a protein-based vaccine, so you simply make those spike proteins in the laboratory."
The Novavax jab, which is a protein subunit vaccine, is produced by genetic engineering and grown in moth cells.
It uses the same technology that has been used in vaccines for hepatitis B, HPV, and whooping cough — a technology Novavax has described as a "tried and true" platform.
"I think because of that, a lot of people have a level of comfort with this vaccine that we haven't seen with some of the others," Dr Griffin said.
While Pfizer and Moderna's COVID-19 vaccines are the first mRNA vaccines to be approved for human use, the technology they're based on has been around for years.
Is the Novavax vaccine safe and effective?
Two large phase 3 clinical trials — conducted in the US and Mexico, and in the UK — found Novavax had a 90 per cent efficacy rate at preventing symptomatic infection.
Prevention against severe disease varied from 87 per cent in the UK trial to 100 per cent in the US and Mexico trial.
Across these trials, approximately 27,000 people received two doses of the vaccine, and approximately 17,000 received a placebo.
But the trials were conducted before the emergence of the Omicron variant, and the company says it's conducting further studies on the efficacy of the vaccine against newer variants.
"We do have [emerging] data that show that we have cross-reactive immune responses against Omicron and other variants that emerge, so that's really exciting news," Silvia Taylor, a senior vice-president at Novavax, told RN Breakfast.
When it comes to vaccine safety, clinical trials have indicated no major signals of adverse events.
The most commonly reported side effects include headaches, muscle pain and fatigue, and these tend to occur more frequently after the second dose of the vaccine.
Will Novavax be used for boosters? What about kids?
Novavax doesn't currently have approval to be used in children or teenagers, or for booster shots.
But studies into its use for both are ongoing.
"I know there is interest in the potential of Novavax being used as a booster, or even in adolescents, or as a paediatric dose," Professor Skerritt said.
"The company hasn't yet submitted an application to us for that, but we're talking to them."
Novavax recently announced that preliminary data showed its vaccine was 80 per cent effective in children aged 12 to 17.
Clinical trials in this age group were conducted when the Delta variant was predominantly circulating.
Ms Taylor said Novavax planned to submit applications for an adolescent vaccine to drug regulators in the coming months.
"And then we'll step down into younger populations — children younger than 12 years of age," she said.
She added that other preliminary data suggested Novavax could be used as a booster vaccine.
"We have data that shows our vaccine provides a high level of immune response when used as a booster … so that will definitely be a possibility."
It's also expected that the Novavax vaccine will be given to low- and middle-income countries as part of Australia's vaccine donation program.
Unlike mRNA vaccines, the Novavax vaccine doesn't require ultra-low temperatures and can be stored in fridges for up to three months.
