Australia secures 10m additional COVID vaccine doses

Prime Minister Scott Morrison confirmed the latest additions to Australia’s vaccine stocks at a joint press conference with Federal Health Minister Greg Hunt and Department of Health Secretary Professor Brendan Murphy.
 
Australia has now arranged access to 150 million doses of three different coronavirus vaccine candidates – pending regulatory approval – which Professor Murphy said is a ‘very, very nice position to be in’.
 
‘All of these three vaccines have now been shown to be highly effective at preventing clinical COVID disease, and particularly severe COVID disease,’ he said. ‘That is a position that we wouldn’t have dreamt of a year ago, six months ago.’
 
Minister Hunt said Australia had included an option in its initial contract with Pfizer/BioNTech to purchase more doses should the Therapeutic Goods Administration (TGA) approve the candidate, which was triggered late last month once it was given the green light.
 
The announcement was only the latest in a series of recent developments related to Australia’s coronavirus vaccination program, which is due to begin in the coming weeks.
 
Pfizer/BioNTech
Pfizer/BioNTech’s COMINARTY vaccine is the first, and so far only, coronavirus vaccine candidate to have been approved by the TGA.
 
Concerns had previously been raised about its suitability for use among the elderly, but earlier this week the TGA confirmed there is ‘no specific risk’ associated with its use among older patients and did not impose any limits on its use. 
 
The decision cleared the vaccine for use in residential aged care facilities during phase 1a of Australia’s COVID-19 vaccine roadmap, while the latest announcement means Australia has secured 20 million doses of the 95% effective mRNA candidate.
 
The first shipments are due to reach Australia within weeks, and Minister Hunt again reaffirmed his belief that the doses would arrive on schedule, despite the EU imposing new export controls on locally manufactured vaccines due to a shortage in Europe.
 
The vaccine is among the most effective to have completed widespread clinical trials, but comes with a number of drawbacks – including the need to be stored at -70°C, and its sensitivity to movement.
 
Australia is also currently unable to manufacture this type of vaccine domestically, although the Government is exploring whether this could be done in future.
 
Doses are expected to be administered 21 days apart, although new (non-peer reviewed) data from the mass rollout across Israel shows it may still be 90% effective after only one dose.
 
Oxford University/AstraZeneca
AZD1222 was the first coronavirus vaccine candidate secured by the Government for widespread use in Australia.
 
An initial order of 34 million doses was augmented with another 20 million doses following the withdrawal of the University of Queensland candidate, bringing the total number available to 54 million – the most Australia has of any one candidate.
 
While the first batch of AZD1222 is likely to be imported, Melbourne-based CSL will manufacture the majority of doses used in Australia, with the first round of domestically-produced doses likely to be available by March.
 
However, while the Oxford University/AstraZeneca-developed vaccine has some advantages over Pfizer/BioNTech’s candidate, such as cost, less onerous cold chain requirements, and the ability to be manufactured locally, its development has not been without controversy.
 
Major phase 3 trials were paused last September due to a ‘potentially unexplained illness’ that turned out to not be related to the vaccine, while questions have swirled around its efficacy.
 
Phase 3 results indicate it is anywhere between 60% and 90% effective at preventing infection, but inferior trial design has meant there is limited data available on its viability in people aged 65 and over. Likewise, the 90% efficacy rate was only found in a small group of participants – all aged under 55 – who accidentally received a lower dose as a result of a manufacturing error.
 
But, even though it has a lower efficacy than Australia’s other candidates, it has still so far demonstrated complete protection against severe disease.
 
If approved by the TGA, AZD1222 is the vaccine GPs are most likely to administer, primarily due to its availability and lower cold chain requirements. This will occur from phase 1b onwards, which is due to start in late March or early April.
 
At this stage, people will need two doses 28 days apart to receive maximum protection.
 
Novavax
Australia has secured access to 51 million doses of Novavax’s NVX-CoV2373 candidate, which is still undergoing phase 3 clinical trials.
 
Interim results suggest the ‘subunit’ vaccine has an efficacy of 95.6% against the main COVID variants and 85.6% against the UK variant. However, phase 2b clinical trials in South Africa found it only possessed around 60% efficacy against the new 501.v2 variant in HIV-negative participants, which dropped to just below 50% when including HIV positive participants.
 
Like AstraZeneca’s candidate, NVX-CoV2373 can be manufactured domestically, although that is unlikely to occur until CSL has fulfilled its commitment to AZD1222 due to a lack of capacity.
 
It is not known when the ongoing phase 3 clinical trials, underway in the US and Mexico, will be completed, nor when or if it will be approved by the TGA. However, its high efficacy and traditional cold chain requirements mean it may form a key pillar of Australia’s vaccine strategy.
 
If successful, it will require two doses, 21 days apart.
 
COVAX
Australia has committed $123.2 million to be part of the purchasing mechanism of the joint COVAX facility, which provides access to a large portfolio of COVID-19 vaccine candidates and manufacturers across the world.
 
The deal means Australia can receive offers to purchase 25 million vaccine doses if and when they become available.
 
Potential COVAX Facility vaccines include Novavax and AstraZeneca candidates, along with ones produced by Moderna, CureVac and five other companies that have not yet progressed past phase 2 clinical trials.
 
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