In most people, chicken pox only occurs once and the body then has a natural immunity to the virus for life, according to Johns Hopkins Medicine Health Library. However, in some very rare cases, a second bout of chicken pox has been known to occur.
The virus that causes chicken pox always remains in a dormant state within the nerve tissue once contracted, and can subsequently cause herpes zoster, or shingles, according to Johns Hopkins Medicine Health Library. For people who are unsure if they have ever had chicken pox, a simple blood test can confirm immunity to the virus. Chicken pox, which typically appears during childhood, is highly contagious. Since 1995, a vaccine has been available to prevent the spread of chicken pox.