No obvious barriers for GP involvement in potential Moderna rollout

US pharmaceutical company Moderna this week announced 10 million doses of its mRNA-1273 COVID vaccine could arrive on Australian shores by the end of the year, while another 15 million of its updated variant booster candidate will be delivered in 2022.
 
Pending Therapeutic Goods Administration (TGA) approval, the Moderna vaccine deal will supplement agreements the Australian Government has in place for almost 170 million other vaccine doses with Pfizer, AstraZeneca and Novavax.
 
Federal Health Minister Greg Hunt later stated that around one million Moderna doses will be delivered before 30 September, with the remaining nine million to arrive by the end of this year.
 
He added that the shipments will provide ‘flexibility’ for the rollout strategy and ensure the under-50 cohort will be covered, following the recent decision to recommend AstraZeneca only be used in those aged 50 and older, and that the 15 million ‘booster’ candidates will help deal with emerging variants of concern.
 
Professor Thomas Preiss, an RNA biologist from the Australian National University, told newsGP this is a ‘very good’ strategy.
 
‘mRNA vaccines are ideal for this sort of adjustment, as their specific “payload” sequence can be rapidly altered to cover new variants,’ he said.
 
‘Having the flexibility to boost resistance in already-vaccinated people during 2022 may well be required.’
 
The Moderna announcement comes after Stanley Erck, the CEO of Novavax, confirmed another delay in efforts get its vaccine into the market, due to an ongoing shortage of raw materials. Australia has a deal in place to purchase 51 million doses of Novavax’s candidate, should it pass phase 3 clinical trials.
 
No such delays are expected in terms of Pfizer fulfilling its contract to supply a total of 40 million doses of its COVID vaccine by the end of the year.
 
It was revealed during this week’s presentation of the Federal Budget that Commonwealth vaccine centres (formerly GP-led respiratory clinics) will be involved in the distribution of Pfizer, but there is no such clarity regarding standard general practices, which to date have only received doses of AstraZeneca.
 
Speaking at the most recent Department of Health webinar for GPs involved in the COVID vaccine rollout, Deputy Chief Medical Officer Professor Michael Kidd said it was still ‘too early’ to say whether general practice will be involved in any rollout of the Moderna vaccine.
 
However, while the mRNA-1273 candidate relies on similar technology to Pfizer, its cold-chain requirements are far less onerous, potentially paving the way for greater GP involvement in any subsequent rollout later in the year.
 
Professor Preiss says available advice from the TGA and US Centers for Disease Control and Prevention (CDC) indicates Moderna has a number of logistical advantages over Pfizer.
 
‘In terms of shipping and long-term storage, the key difference is that Pfizer requires temperatures below -60°C, while Moderna requires a -50°C to -15°C range,’ he said.
 
‘The latter is achievable with readily available freezer technology, while the former requires ultra-cold freezers and/or dry ice.’
 
Pfizer’s vaccines can be stored in a regular freezer for up to two weeks, whereas Moderna can be stored in a regular freezer for up to six months.
 
Neither vaccine can be refrozen once thawed for use, but the Moderna vaccine is ‘ready to use’ once in a liquid state. The Pfizer vaccine, on the other hand, needs to be brought up to room temperature for two hours before administration and requires the addition of a diluent prior to use.
 
‘Again, the Moderna vaccine has somewhat more relaxed requirements here than Pfizer,’ Professor Preiss said.
 
‘Unpunctured [Moderna] vials may be stored in a refrigerator between 2–8°C for up to 30 days, or may be stored between 8–25°C for a total of 24 hours.
 
‘[Conversely], unpunctured Pfizer vials stored in the freezer can [only] be transferred to the refrigerator for an additional five days.’
 
Finally, punctured Moderna vials can be kept between 2–25°C and must be administered within 12 hours, in comparison to punctured Pfizer vials, which must be used within six hours when kept at the same temperature range.
 
Nearly $234 million was earmarked in the Federal Budget to ensure the safe distribution of vaccine doses around Australia, including cold-chain storage, logistics, and the supply of necessary consumables.
 
Moderna, which requires two doses 28 days apart, has so far been used in vaccine rollouts in France, Singapore, Qatar, the US and the UK, and clinical trials indicate is has an efficacy of 94.5% in terms of preventing COVID-19.
 
Recent reports also suggest it is effective against the B.1.617 variant of concern, while Moderna has said its booster should be protective against the B.1.351 and P.1 variants.
 
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