How does a person get chicken pox more than once?

[expatinscotland]

Are there different strains? Did their immune system fail?

I've heard anectodatal stories of this happening, but never witnessed it myself.

Yikes!

I had CP as a baby - 18 months - and it was a pretty mild case.

But I've been exposed to it more times than I can count - including in 2nd grade when so many went down w/chicken pox they cancelled lessons for days - and never got it again (touch wood).

I don't really understand it. I caught chicken pox in my thirties (it was really bad ) but my dd who was 2, and with me all the time, never caught it - she waited until she was 6.

A friend of mine just had chickenpox for the 2nd time. The Dr told her that sometimes people can get re-infected - whatever that means!