Technically the T-Virus does more than zombies. It makes giant and/or zombie animals, combined with genetic mutation will create creatures like Hunters and the plant monsters, will mutate zombies into Lickers after enough time has passed, and if the subject has the right genetic makeup they'll become Tyrants (which is what the "T" in T-Virus stands for).
Don't forget Crimson Heads.
If you'd played RE5, you'd know this has already happened. (okay they were Majini but close enough)
Right, but aren't these T-Virus zombies?