Ganciclovir
Ganciclovir has also been used with some success in treating "Human herpesvirus 6" infections.
Human herpesvirus 6
Active infections involve the linear dsDNA genome circularizing by end to end covalent linkages. This process was first reported for the herpes simplex virus. Once circularized, HHV-6 begins to express what are known as "immediate early" genes. These gene products are believed to be transcription activators and may be regulated by the expression of viral micro RNAs. Subsequent expression of "early genes" then occurs and activates, for instance, viral DNA polymerases. Early genes are also involved in the rolling circle replication that follows.