I think there is no doubt that he could be helped that quickly. If the med he's on is just right, and the inflammation in his lungs is mild, it wouldn't take a lot to get him better. I'm glad to hear that he has responded so well. Sounds like Symbicort is a good drug. I know that Aurora has been helped greatly by it.
My asthma is doing much better. Although I'm still getting allergy symptoms (hoarseness, some mucous), my lungs are really doing great. Not perfect, but no wheeze, no cough, unless I'm raising the small amount of mucous my lungs are producing. It's a great feeling. Hope it lasts. Grass pollen is on its way soon!
Hope your asthma is doing well.