It could soon be possible to temporarily boost people’s immune systems to fight off all sorts of diseases, including anthrax.
The method is based on a key difference between human and bacterial DNA. In people, when the bases cytosine and guanine occur together, the cytosine usually carries a methyl group. In bacteria, it doesn’t.

Several teams are now developing synthetic CpGs that trigger this response. They have shown great promise in initial studies. Because a generalised response is quick and non-specific, it should protect people exposed to a wide range of bacteria, or to strains against which vaccines don’t work.