Ganciclovir
Ganciclovir has also been used with some success in treating "Human herpesvirus 6" infections.
Human herpesvirus 6
Researchers have demonstrated that levels of HHV-6 IgG1 and IgM antibodies are elevated in MS patients relative to controls. In fact, research published in 2014 found that increases in anti-HHV-6A/B IgG and IgM titers are predictive of MS relapse.