https://en.wikipedia.org/wiki/Marek%27s_disease#Prevention is the canonical example: "However, the leaky vaccine changes this evolutionary pressure and permits the evolution of highly virulent strains. The vaccine's…
https://en.wikipedia.org/wiki/Marek%27s_disease#Prevention is the canonical example: "However, the leaky vaccine changes this evolutionary pressure and permits the evolution of highly virulent strains. The vaccine's…