How is it possible to get shingles disease?

Reactivation. Shingles is a reactivation of the chicken pox virus (varicella-zoster) that lives dormant in nerve cells after the initial chicken pox infection.
Shingles . Shingles is caused by the same virus responsible for chicken pox . The virus remains in a dormant state until a shingles outbreak occurs years later when the immune system is weakened or during stressful times.