My wife used to get upper respiratory infections all the time. Used a lot of Antibiotics , So got an ultrasonic nebulizer and put in the 20ppm CS and she would use this every time she thought something was comming on. It has been over 4 1/2 years since she has had an infection. My 25 year old daughter had a bad chest infection and used the ultrasonic neb., in 3 days she was better and the doctor told her to come back in and found her to almost completely well. The doc wanted to know what she used, she told him and he did not say much except to continue on with what she was doing as it was working. I need to get another nebulizer(ultrasonic) they work very well, nedd to have one at my daughters place.