Even with the best-case scenario, when someone recovers from CFS in a very short period of time, since most of the viruses implicated with CFS (including EBV) belong to the herpes family, at best the virus will be brought down to a normal state in the blood: permanent latency/remission. The normalcy can last a lifetime, and will, unless the patient gets into a situation of unrelenting and unendurable stress.
Thus, a proper strategy for the treatment of CFS is to adopt a long-term (lifelong) program for the prevention of relapses, not merely stimulating the immune system and supporting the metabolism to deal with the current stressors in your life. In a nutshell, this means both the patient and physician must focus on quality of life.
(Source: Chronic Fatigue Syndrome: The Hidden Epidemic, by Jesse E. Stoff, M.D., and Charles R. Pellegrino, Ph.D.)