Ganciclovir
Ganciclovir has also been used with some success in treating "Human herpesvirus 6" infections.
Herpesviridae
Nine herpesvirus types are known to infect humans: herpes simplex viruses 1 and 2 (HSV-1 and HSV-2, also known as HHV1 and HHV2), varicella-zoster virus (VZV, which may also be called by its ICTV name, HHV-3), Epstein–Barr virus (EBV or HHV-4), human cytomegalovirus (HCMV or HHV-5), human herpesvirus 6A and 6B (HHV-6A and HHV-6B), human herpesvirus 7 (HHV-7), and Kaposi's sarcoma-associated herpesvirus (KSHV, also known as HHV-8). In total, more than 130 herpesviruses are known, some of them from mammals, birds, fish, reptiles, amphibians, and mollusks.