When is Teemo going to benefit from Spell Vamp?

Teemo is the only Champion I know of that doesn't benefit from Spell Vamp. His E even though it is AP doesn't work with spell vamp but his Shrooms do?

Don't work with teemo and they should. Or is it because it's a passive ability instead of an active ability? In which case that is stupid.

I think even aids would with Spell vamp.