pokerus eventually wears off if the affected Pokemon is still in your party. It won't wear off if
the affected Pokemon is stored in your pc. But pokerus helps you get experience points faster from defeating opponents and wild Pokemon. pokerus might spread to the rest of your team
if a Pokemon with pokerus is in your team. After pokerus wears off, a smiley face will appear in the top right corner of your Pokemon summary menu.