Poison Spell Damage to Archers Queen

Hi , i have one question about the "poison spell" , at level 3 the damage is max 450 , my enemy queen are level 16 ( so 990 health ) , i use 2 poison spell on queen ( queen remained inside the circle ) but her health is more than half ( 3/4). With the queen there're a dragon level 4 and 3 balloons level 6.

How exactly work the poison spell ?
Thanks for the answer

It doesn't effect heroes like regular troops, they take very little damage from the poison spell. It's changing next update, so look at the sneak peeks up top and watch the video.

Thanks for the answer Micker ;D

From the vids I've seen they'll hardly hurt heroes post update too.