Yes. I've been on Valcyte for almost 3 weeks. Started at a high dose and can drop to a maintenance dose on Friday. It will take at least a few months to know if it is working but I have good reason to think it will. Valcyte is a very kick-ass drug for herpes viruses, but VERY expensive if you don't have insurance in the US. I am not sure how it works in the UK. The thing about viruses like HHV-6 is that almost everyone has had them as a child, so a lot of doctors will tell you that positive antibodies just mean that you had the disease once and don't indicate they are a problem now (I had an infectious disease "specialist" refuse to even test me because of that). Of course that's bullshit. Just like the chicken pox virus (also in the herpes family) can reactivate later in life as shingles, HHV-6 and EBV can reactivate as neurologic viruses and cause CFS symptoms among other things. You want to get tested for early antigen in the case of EBV (no one who had mono as a child should have early anitigen antibodies now) and IgG (long-term anitibodies) for HHV-6. A normal HHV-6 IgG result for someone who had the disease (roseola, I believe) as a child is 1:80. 1:320 is considered very high. Mine was 1:1280.