Chickenpox is caused by the varicella zoster virus. It can be spread either through close person-to-person contact, or through sneezing and coughing just like a cold or flu. Later in the illness, the virus is spread by direct contact with the fluid in the blisters. Chickenpox infection triggers an immune response and people rarely get chickenpox twice.
The infection is highly contagious to people who have never had chickenpox or who have not been vaccinated. You can also catch the virus by handling items and surfaces that have been contaminated, then transferring the virus to yourself by touching your face.
Children can develop chickenpox after being in contact with someone who has shingles. Anyone who has had chickenpox can develop shingles. People who have never had chickenpox can catch the virus from another person with shingles, but in this case they would develop chickenpox (not shingles).
Last reviewed: October 2016