This study includes a section on what happens to the CD8 cells of the immune system during a chronic infection. It makes me wonder if the negative impact on the Tcells is why it is so hard for people with CFS to get their viral infections under control. I see , time and time again, people who do well while on antivirals but relapse shortly after stopping. I don't know what the solution to this is. I haven't looked into this at all yet but am wondering if stem cells would help. http://jvi.asm.org/content/78/11/5535 - Viral infections can be largely divided into two types: (i) acute infections, where virus is eliminated; and (ii) chronic infections, where virus persists. This second type of infection may be further classified into latent infections and those in which there is persistent viral replication. While acute infections usually result in effective antiviral immune responses, chronic infections can be associated with suboptimal T-cell function - "When compared directly, several aspects of a normal CD8 T-cell response are altered during a chronic infection. - First, the pattern of immunodominance, the hierarchy between responses that are high frequency, or immunodominant, and those of lower magnitude, or subdominant, can be dramatically skewed. For example, during chronic LCMV infection of mice, subdominant specificities often come to predominate the LCMV-specific CD8 T-cell response (37, 122, 129, 138). A similar pattern of inverted immunodominance has been observed during persisting mouse hepatitis virus infection (16) and simian immunodeficiency virus (SIV) infection of macaques (33). - Second, the tissue distribution of antigen-specific CD8 T cells can differ from that observed following acute infections, with a large number of virus-specific CD8 T cells present in nonlymphoid tissues (50, 83, 129), driven by antigen localized in these compartments or differences in the expression of homing molecules expressed by the CD8 T-cell populations generated during chronic infection compared to those generated during acute infection. - Third, chronic infections can result in severely impaired T-cell function (functional exhaustion) and/or the physical elimination of responding T cells (deletion)."