My doctor told me that adults could take the vaccine if they wanted to.  All 3 of my siblings had chicken pox and although I was exposed all 3 times, I never caught it.  My daughter was exposed before she took the vaccine and she did not catch it either.  The pediatrician felt that it was best for her to have the vaccine because adrenal crisis tends to happen more when they are younger.  She has not had nearly as many crisis as when she was age 6 and younger.  He felt that if she caught it later in life she would be able to handle it better and possibly not go into adrenal crisis.  It sounded good to me at the time because CAH was so new to me.  Now I wonder if she should not have had the vaccine.