Shingles is a "second coming" of chicken pox but I am not sure wether chicken pox proper can be had twice. Shingles is not inevitable but frequently occurs much later in life and then it does because the virus is still resident in the former chicken pox patient.
I had chicken pox as a child and I had it (not shingles) as an adult too. My second dose of chicken pox was the most unpleasant thing I have ever experienced and I was off work for weeks.
Why hasn't anyone asked what the chickens think about you putting their pox down. im sure they're not happy about you calling the condiotion after them. They would probably prefer you to call it the fox pox, as 1) the fox is the chicken's longest advesary and 2) because it rhymes.