. A second is manufacturing. In contrast to traditional vaccines, says Kis, 'there are no living cells involved in the making of the RNA. It's synthetic. A biochemical process, simple, easy to purify it and to show quality, a much cleaner approach.' Much less also goes much further. 'Ten litres of RNA could make as many doses as 1,000 litres of the conventional process.' Kis sees three stages to develop the potential of mRNA therapies. In the immediate term, they can be directed at infectious diseases like Covid, which Kis calls 'the low-hanging fruit'. In the long term, they can be used to deliver gene-editing tools inside the body to fix inherited diseases like sickle cell. In the medium term, however, Kis sees the advent of personalised cancer vaccines. Weissman explains how they would work: 'You take out a piece of lung tumour or breast cancer or colon cancer or melanoma and sequence it' to reveal its genetic code. Such codes in cancer have many mutations, and a vaccine is based on those specific mutations, prompting the immune system to attack the cancer cells while leaving the body's cells unharmed. The technique has been shown to work well in melanoma, and less so in other cancers. But BioNTech already has one cancer vaccine in a phase two (of three) trial 'looking at a whole bunch of different cancers'. As with many cutting edge techniques, the cost of such a vaccine would currently be prohibitive – 'probably hundreds of thousands of dollars' says Weissman. But as the plunging price of gene sequencing has shown, costs can tumble dramatically as breakthrough technology becomes widely adopted. It is in genetic medicine that Weissman hopes to make the biggest breakthrough, by loading up his RNA courier with a gene-editing tool called Crispr. The problem is hitting the right target in the body – typically the particles end up in the dendriti){kind=link}
Scientists are learning to harness a ‘game-changing’ technique that has the potential to defeat a range of humanity’s deadliest foes
Drew Weissman is not ready to rest on his laurels. He’s already thinking about the next coronavirus variant – the one that will come after the Indian variant, or the Kent variant or the South African variant, and demolish the defences of our vaccines. Or rather, to give him his due, his vaccines.
“Moderna has already started a clinical trial with the South African variant,” he says. “Pfizer is doing the same. My concern is, I don’t think that’s the right approach.” Soon enough, he says, pharma companies will have to update again, and then again, in an eternal battle of cat and mouse.
Wouldn’t it be better, he says, if Covid vaccines worked not by identifying what makes variants different but against what they have in common. He’s doing just that. “We’re making a vaccine that will protect against every variant that’s ever been produced and should protect against all possible variants that appear in the future.”
It’s a bold claim. But Weissman isn’t finished there. “We’ve had three coronavirus epidemics in 20 years [Sars, Mers and Covid]. It would be foolish to think we’re not going to have more. So we’ve also been working on our pan-coronavirus vaccine.”