The UK has become the first country to approve one of the coronavirus vaccines that the entire world has been desperately waiting for. And on Tuesday it delivered the first dose, to 90-year-old Margaret Keenan in Coventry. We should be very pleased about this. But, as with every other stage of the pandemic, the final stretch brings a new set of unprecedented challenges. The world is watching as the UK becomes the first test case of our collective ability to manufacture, ship, and deliver an entirely new class of vaccines, on a scale and speed that no previous vaccination drive in history has ever approached.
The thing everyone knows about the Pfizer-BioNTech vaccine is that it needs to be extremely cold. The mRNA that makes up the vaccine payload is the same stuff your cells use to send short-lived genetic instructions. It’s a messenger that isn’t supposed to stick around, as temporally fragile as a Snap on Snapchat. The vaccine is happiest at -70C, and after thawing can be kept at between 4C and -8C – the temperature of a regular fridge – for just five days before it degrades. Most logistics providers aren’t set up to ship at -70C, and while university labs and large hospitals generally have some -70C freezers, GP surgeries and smaller centres do not. The temperature for shipping and storage has been identified as one of the biggest challenges in getting this vaccine out.
The Pfizer/BioNTech Covid jab is an mRNA vaccine. Essentially, mRNA is a molecule used by living cells to turn the gene sequences in DNA into the proteins that are the building blocks of all their fundamental structures. A segment of DNA gets copied (“transcribed”) into a piece of mRNA, which in turn gets “read” by the cell’s tools for synthesising proteins.
Stephen Buranyi is a writer specialising in science and the environment
