Trial RNA vaccines have failed, however, after being destroyed rapidly in the blood. But CureVac, a company in Tübingen, Germany, has found that a protein called protamine, binds to mRNA and protects it. It has an mRNA vaccine against prostate and lung cancer tumours in human trials.
A true universal vaccine for flu, however, would induce immunity to proteins that are the same in all flu viruses, but which flu normally hides from the immune system. Stitz’s team made an mRNA vaccine to one such protein from an ordinary seasonal flu. The vaccine not only protected animals from that flu strain, but also from H5N1 bird flu.