Originally Posted by
T-1000
I would assume that standard anti vampire weapons would be effective against Dio and anti-vamp weapons is all Anderson is packing. Without any evidence to the contrary, there's nothing to suggest he'd be immune. He at least shares the same standard weakness to sunlight.
His stand of course is another matter, so that definitely presents a problem. But at least for the first round, I'd say Anderson takes it. The second depends on whether or not his vines and tendrils can reach Dio and how long he can hold out against Dio's time stop.
EDIT: Also, as far as Dio's healing goes, Dio doesn't have regen, he has quick heal. He can reattach severed limbs and definitely heal quickly (in Phantom Blood, he could heal faster than fire could burn him) but he doesn't have the ability to regrow lost tissue, as evidenced by his needing a new body after being self-decapitated.