The biggest problem now is that we (the medical profession) are not exactly sure how long the varicella (chickenpox) vaccination is good for. There have been some studies that show waning protection after about 10 years or so. Whereas, if you actually catch chickenpox, then the immunity is good for lifetime. So in a sense, it's almost better to catch chickenpox as a child to make sure that you don't get chickenpox as an adult (it tends to be a much worse disease in adults than in children). As to whether getting varicella immunizations as a child is necessarily a good thing in terms of future immunity, only time will tell ...

Masaki