> what could be the simplest trigger? what biologists call "cell stress" as well as dna damage. you gotta consider that both for the ancestral virus were signs the host cell might be dying soon ... so to "leave the sinking ship" it had to reawaken and replicate. what keeps it asleep is the cellular defense against just such types of parasites ... which comes down to their little stretch of dna being packed so tightly that it becomes inaccessible (and therefore dormant). this is where dna breaks can trigger a nasty little trap by the virus. to repair a break the damaged stretch needs to be unpacked ... and usually gets repackaged quickly once the damage is removed. but if the break is within the virus it will prevent the repackaging (by keeping the "to be repaired" mark on the once damaged stretch active indefinitely). pretty neat trick, well, for the virus at least. now "stress" might achieve something similar, directly or indirectly ... little shits can be like swiss army knives when it comes to that. would need to get back into the literature. it gets a bit complicated here as we also gotta consider that a cell "sensing" an activated virus will often try to commit suicide, take the virus down with itself. many viruses (like hpv) actively try to prevent that suicide program, which also means the cell will not commit suicide once it has lost terminal control of its genomic stability (which might then reawaken the dormant virus etc etc).
Gadsden