After more than two years of the COVID-19 pandemic, you might picture a virus as a nasty spiked ball – a mindless killer that gets into a cell and hijacks its machinery to create a gazillion copies of itself before bursting out. For many viruses, including the coronavirus that causes COVID-19, the “mindless killer” epithet is essentially true.
But there’s more to virus biology than meets the eye.
Take HIV, the virus that causes AIDS. HIV is a retrovirus that does not go directly on a killing spree when it enters a cell. Instead, it integrates itself into your chromosomes and chills, waiting for the right moment to command the cell to make copies of it and burst out to infect other immune cells and eventually cause AIDS.
Exactly what moment HIV is waiting for is still an area of active study. But research on other viruses has long hinted that these pathogens can be quite “thoughtful” about killing. Of course, viruses cannot think the way you and I do. But, as it turns out, evolution has endowed them with some pretty elaborate decision-making mechanisms. Some viruses, for instance, will choose to leave the cell they have been residing in if they detect DNA damage. Not even viruses, it appears, like to stay in a sinking ship.
