Respiratory Syncytical Virus (RSV) is not a 12-week illness. What may have started as RSV may be something else right now.
ReactiveReactive arthritis Airways Disease (RAD) is a state when a child has been wheezing and the cause is not necessarily defined. When this is short term associated with a particular virus, it is RSV. When this lasts for a longer period, it is often called asthma.
The medications used most often for the treatment of this problem are bronchodilators (ventolin is one of these) and steroids. Using inhalers in 10-month-old children is very difficult. They do not inhale very well and thus the medication is not delivered very well to the lungs. If the wheezing continues to be a problem, I would suggest seeing a specialist who will most likely recommend using a nebulizer.