Since the start of the pandemic, far more attention has been paid to developing a vaccine than to the sticky process of actually getting that vaccine, once developed, to people.
As the first vaccines near possible approval, though, that question is gaining urgency, and it’s posing a particular problem for the new technology that has allowed some of these candidates to move so quickly: mRNA. To remain stable, mRNA vaccines have to be stored at incredibly low temperatures — as low as -80 degrees Celsius (-112 Fahrenheit). Distributing them, experts have warned, poses a major logistical challenge for the US and an even greater challenge to the world.
On Wednesday, Moderna alleviated some of those concerns. At a meeting for Advisory Committee on Immunization Practices, the now household-name company said that its vaccines would have to be stored long-term at -20 degrees Celsius and kept in normal vaccine refrigerators for around 7 days. That’s still a challenge, but it imposes fewer demands than some had feared. It was also noticeably less strict than what BioNTech and Pfizer, presenting on the same day, said they would need for their jointly-developed mRNA vaccine: Long-term storage at -70 degrees, and only 24 hours of standard refrigeration.
The differences have implications both for who gets a vaccine and when and for the investor-watched race for Covid-19 market share. Towards the end of the meeting, CDC medical officer Kathleen Dooling sketched different distribution plans depending on if Moderna’s vaccine is approved, if BioNTech’s is approved, or if both are approved. If Moderna came first, it would “require diligent vaccine management to minimize waste,” she said. A BioNTech approval, on the other hand, would all but eliminate community clinics and local pharmacies from the initial rollout. Healthcare workers at “centralized sites with adequate equipment and high throughput” — e.g. large, urban hospitals — would take priority.
Nancy MessonnierNancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, noted the challenges with BioNTech’s approach.
“The complexities of this plan for vaccine storage and handling will have major impact in our ability to efficiently deliver the vaccine,” Messonnier said after their presentation, as Reuters reported.
Analysts agreed that less stringent requirements could give Moderna an “advantage,” as SVB Leerink’s Mani Foroohar put it, but they acknowledged that advantage may be temporary or limited. The other vaccine approaches, such as viral vector or recombinant protein, don’t tend to require such glacial storage conditions and will likely be easier to distribute when they arrive.
Novavax has said their recombinant protein can be kept in a standard vaccine refrigerator. Endpoints News has reached out to the rest of the leading US-backed vaccine companies about their requirements, as well as to CureVac, the third major company developing an mRNA Covid-19 vaccine. Merck said in an email they initially plan to store their viral vector vaccines at -70 celsius but are working toward storing “at more typical refrigerator conditions.”
The darkhorse mRNA vaccine effort, Sanofi-partnered Translate Bio, said in May they were attempting to come up with a formulation that can be stored at warmer temperatures. But they have said little of the effort since.
