A rare genetic mutation appears to make people basically invulnerable to viruses – and it could potentially be harnessed as a therapy. Researchers have now shown this surprising viral protection can be replicated in mice and hamsters.

“We have yet to find a virus that can break through the therapy’s defenses [in cell culture tests],” explains Columbia University immunologist Dusan Bogunovic, who first discovered this unusual antiviral superpower 13 years ago.

The mutation, a deficiency in interferon-stimulated gene 15 (ISG15), causes a mild yet persistent inflammation across the body. Examining patients’ immune cells revealed they’d had the usual run of encounters with flu, measles, chickenpox, and mumps, yet they’d never reported feeling particularly ill as a result.