What is the cause of chickenpox?

Chickenpox is caused by the varicella-zoster virus (the same virus that causes shingles). Chickenpox is very contagious and the virus spreads most easily from individuals who have the rash. It can be transferred from contaminated surfaces or the tiny droplets that come out of the nose and mouth of those who are carrying the infection when they cough or sneeze.

Children who have had chickenpox before should not catch it again and have immunity against the disease for the rest of their lives.