both have pretty weak early games, but as irelia at what levels is it best to play aggressive?

Irelia levels 2-5 should wreck Vlad, then she'll get weaker for a bit, and come back hard mid-late game.

Irelia can definitely win this lane if she plays aggressively enough, if she just passively farms though vladimir will outscale her hard.

Assuming equal farm, i think vlad will always have bigger teamfight presence than irelia unless she manages to dive the AD carry and kill them before the enemy team reacts.