mRNA drugs with a built-in ‘copy machine’ could lead to safer, more effective therapies

Remember that messenger-RNA-based Covid-19 vaccine you got? Just a few days later, the teeny molecular messengers contained in the shot were already gone.

Despite scientists’ best attempts to bolster mRNA and improve its stability, these molecules are ephemeral.

That’s not necessarily a bad thing. A short, sharp burst of protein can be enough to rev up an immune response. And for gene therapies, the brief lifetime of mRNA is a major plus — you wouldn’t want DNA-cutting enzymes running rampant in your cells after they’ve already made a helpful genetic edit.

In some cases, however, a patient might need to produce high levels of a therapeutic protein for a prolonged period of time to benefit from a treatment.