For millions of years, humans and viruses have engaged in a constant tug of war: as our cells evolve new ways to defend us from our viral enemies, these pathogens in turn acquire new traits to sidestep those defenses.
For millions of years, humans and viruses have engaged in a constant tug of war: as our cells evolve new ways to defend us from our viral enemies, these pathogens in turn acquire new traits to sidestep those defenses.