Blood clots, supply issues, new technologies: Does Australia need another COVID vaccine option?

*This story was updated on Thursday 15 April at 8.00pm to reflect that Sinovac and Sinopharm are inactivated whole-virion vaccines, not protein-based as originally stated.

AstraZeneca has long been flagged as the workhorse of the country’s vaccine rollout, Australia’s best hope for a return to a pre-COVID normal.
 
But since the Federal Government last week made a major – and sudden – change to its vaccination strategy amid concerns over rare blood clots in people aged under 50, that hope has diminished.
 
Australia currently has contracts for three vaccine candidates – Pfizer, AstraZeneca and Novavax.
 
The Government recently upped its agreement with Pfizer for an additional 20 million doses, bringing the total to 40 million, slated to arrive over the course of the year.
 
Interim data for Novavax has it positioned as a promising candidate, with Australia having signed up for 51 million doses. But with phase 3 clinical trials progressing slower than expected, it is unlikely to be available for Australia until later in the year.
 
A heavy reliance on offshore supply and initial vaccination targets well behind the initial schedule have seen questions emerge over whether another vaccine agreement should be sought as a backup.
 
The Australian Government has already ruled out the Johnson & Johnson’s single-dose viral vector vaccine, which has presented with similar issues of rare blood clotting events as seen with AstraZeneca, resulting in the US pausing its rollout, and the company delaying its plans for Europe.   
 
China’s inactivated whole-virion vaccines, Sinovac and Sinopharm, are also in circulation; however, Chinese health officials just this week reported the effectiveness was low, with Sinovac proving to be just 50.4% effective at preventing symptomatic infections in Brazil.
 
Meanwhile, Russia’s Sputnik V vaccine has gained momentum abroad, with India the latest country to sign up. But as another viral vector vaccine, it does not look likely to be a candidate for Australia.
 
That leaves Moderna’s mRNA vaccine as the most promising candidate.
 
Physician and journalist Dr Norman Swan says that with mounting concerns around emerging variants, such as Brazil’s B11248 and South Africa’s B1351, he believes Australia should be focused on acquiring Moderna.
 
‘We didn’t need another 20 million [of Pfizer] just at that point,’ he said. ‘What we need is 20 million or more of Moderna that are geared to the new variants.
 
‘We should be booking Moderna – and we haven’t.’
 
But infectious diseases and vaccine expert Professor Robert Booy believes that between the supply of AstraZeneca, Pfizer and the potential for Novavax, ‘we don’t need a backup’.
 
‘Pfizer are going to deliver … 40 million. That’s going to cover just about everybody,’ he told newsGP.
 
‘The older people who aren’t covered by that are going to be covered by AstraZeneca … so we are in a good position.
 
‘Novavax looks very promising, but it won’t be available for at least another four months. But once it comes online, it will be likely to be a good alternative.
 
‘So we’ve got a redundancy in the system because we’ve got three potential suppliers and two that are on board already. So, essentially, if things go okay from now on, we’re just fine.
 
‘However, if further hiccups arise, we could be embarrassed yet again and we can’t predict the future.’

If all goes to plan, Australia's three vaccine candidates will be adequate, says Professor Robert Booy. 

Stuart Turville, an Associate Professor in the Immunovirology and Pathogenesis Program at the Kirby Institute, believes any further Australian investment in vaccines needs to be based on a long-term strategy, which he says points to RNA technology.
 
‘It’s important to look at what’s happening in terms of the breakthrough infections in the real world and really get an understanding of, if we are to invest strategically in another vaccine candidate, what that would be,’ he told newsGP.
 
‘So it could be Moderna because it’s a very similar technology to Pfizer.
 
‘The thing about the mRNA vaccines, which not a lot of people are talking about, is that the dosing is very fast. So basically within three weeks, you’ve got two doses. That’s a very powerful technology.’
 
Meanwhile, compared to viral vector or protein-based vaccines such as AstraZeneca and Johnson and Johnson, Associate Professor Turville says companies dealing in RNA technology appear to have a faster capability to update formulations to tackle new variants.
 
‘I look at it more in the context of efficacy against what the viruses are that are out there, and see the virus as a moving beast,’ he said.
 
‘The way that we’ve generated vaccines in the past has changed overnight with these mRNA vaccines.
 
‘All of the vaccine manufacturers are doing an amazing job, but … based on what we’re seeing with the quotas, it appears that their scalability, their ability to change the formulations to address specific variants [gives them] a little bit of an edge over the other ones, which may take a little bit longer to update, to produce, and also the turnaround of the boosters as well.’
 
But Professor Booy maintains Australia already has its bases covered when it comes to RNA technology.
 
‘The aim always was to have potentially vaccines from different ways of making it, and so we’ve already got the mRNA approach with Pfizer,’ he said.
 
‘It’s a very expensive vaccine, whether it’s Moderna or Pfizer, we’re paying a high price for it.
 
‘So the fact that we’ve now got a viral vector in the form of AstraZeneca … and then we’ve got a third option in a protein based Novavax, we’re covering the different ways of giving protection.
 
‘So I don’t think we need Moderna.’
 
Federal Health Minister Greg Hunt told reporters on Tuesday that Australia had not sought to secure Moderna because the Government is following ‘medical advice’, as it has done on all of its initial agreements. And the experts providing that advice have yet to recommend Moderna.
 
‘I know some might give views outside the medical advice, that’s their right and their freedom, but the people that have kept Australia safe have been our medical advisers,’ he said.
 
‘When you think of 170 million vaccines for 25 million people, that’s an extraordinary quantity which we’ve been able to secure.’
 
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