Herpesviruses are a group of viruses that can cause several different infections. The disease most people call "herpes," called herpes simplex, is just one of the types of herpesvirus.
Once you're infected with a herpesvirus, the virus stays in your body for the rest of your life. This means that in some cases the virus can become active again. When it does, it may or may not cause symptoms again.
Treatment depends on which type of infection you have. For example, for CMV and some other herpesvirus infections, doctors may give you antiviral medicines. For chickenpox, doctors usually treat your symptoms.
Vaccines can prevent chickenpox and shingles. There are no vaccines for the other types of herpesvirus infection.