University of Toronto researchers have uncovered how bacterial viruses protect their progeny in order to maximize their reach. The phenomenon, described in a study published in Nature, relies on viral proteins to fine-tune structures on the surface of the bacterial host cell and is widely conserved—pointing to a previously unknown parallel between microbial and human immunity.

The researchers dubbed their discovery the anti-Kronos effect, after the Greek god who ate his children.

Researchers have long known that once a cell is infected by a virus, it can block subsequent reinfection by the same or closely related viruses. This process, called superinfection exclusion, was first described in bacteriophages, the viruses that infect bacteria.