Valcyte stops the viruses from replicating, but doesn't outright kill the virus. It's still up to your immune system to do that. My concern is that if you took too low a dose, you might stop the weaker elements of the virus from replicating, but allow the stronger ones to continue. Once you go off the Valcyte, the stronger ones continue replicating and they're not as susceptible to Valcyte, so they're harder to knock down, especially with a low dose. I could be wrong and worrying for no reason, though. I believe both Dr Montoya and Dr Lerner have put patients back on Valcyte if CMV or HHV-6 became active again, so I'm thinking that's not a problem. I wouldn't be popping on and off it frequently, though. I hear they're already seeing Valtrex-resistant EBV. Valcyte may just not be the med for you, especially since you have to work. A lot of, but not all, people feel like crap for some part of Valcyte treatment. Also, Valcyte seems to work best if you can get a lot of rest so your immune system has the energy to kill the virus-infected cells -- those CMV and HHV-6 infected cells must be a bugger to get at. Maybe because they're more likely to be in the CNS than EBV-infected cells? Maybe it would be better to stay on the Famvir and boost the dose if you can...? Have you tried long-term azithromycin for the sinus infection? Or clarithromycin? I've had short-courses of both that helped, but it keeps coming back. I'll be asking my specialist about the whole recurrent sinus thing next time I see her, because I haven't gotten it under control, either.