A cell runs on a fuel called NAD+. Without it, the cell grinds to a halt, like a car with an empty tank. When a virus attacks them, bacteria can burn that fuel so the virus dies along with the cell.
Human NIR was tested in the lab: it cuts NAD+ just like the bacterial version. That means human cells have kept an ancient weapon. Why we still have it is unclear, but it may help transmit signals inside the cell.
The new defense systems Vulcan and Vesta are named after the Roman gods of fire and the hearth, reflecting their ability to "burn" NAD+ during a viral attack.
The idea of a universal molecular switch that destroys a cell's fuel upon invasion is reminiscent of the self-destruct mechanism in "Star Wars," where a ship shuts down all systems so it won't fall into enemy hands.
Not published on arXiv. Here are its page, the PDF and the formalization: you can check it yourself, not only read our account.