Thanks so much for the reply, I actually know that I am fine and am certain that I had it many times as a child. My concern is about my youngest son, who's almost 4. Do you think he's already had the virus? He's had v* episodes (where it was continuous, obviously a virus and not just a flukey thing) about 4 times. I just want to know if it should be assumed he's already been exposed at his age.