>>13661073A virus that kills its host too quickly is unable to properly reproduce. This isn't exclusive to a virus, any foreign thing that needs another living body to survive, such as harmful bacteria, will behave similarly. I don't mean to insult your intelligence, but I'll spell it out for clarity: if a parasite kills its host before the host is able to facilitate further infection, the parasite has failed to reproduce, and any genetic quirks it may have are halted. For this reason, "kills host faster" can often be considered a harmful trait for a virus to have.
The vaccine for Marek's doesn't prevent the disease from occurring. It reduces spread to a degree, but primarily it prevents the cause of death. To put it another way, the vaccine for Marek's is designed primarily for reduction of severity.
Now: what happens when a virus doesn't need to care about how deadly it is? When no matter how deadly it would otherwise be, it is still able to reproduce and infect other hosts?
This doesn't necessarily mean that super-viruses are inevitable, nor that the other dependent factors are necessarily 1:1, but imagining how much "someone" is making from the sale of the vaccine of Marek's disease, it may be worth a raised eyebrow. Or not. Regardless of whoever or wherever they are, people simply being too stupid or lazy, or in a rush, to make the "good" stuff is always an option. On the other hand, a personal favorite theory I hear is that all this is just a cover, a distraction for the REAL shit The Man is doing.
Nobody's asking, but here's my advice: take off your pants, and slide on the ice.
