It is also possible that, inresponse to CMV infection, people with MS are able to overcome the generalCD8+ EM/EMRA T-cell deficiency by augmenting the proportion ofCMV-specific T cells within the decreased total CD8+ EM/EMRAT-cell population, in the same way that healthy subjects maintain an inflated memoryCD8+ T-cell response to CMV.62 Although the CD8+ T-cell response to CMVappears to be normal, the increased frequency of herpes zoster infection in peoplewho develop MS63, 64, 65, 66 raises the possibility of impaired CD8+T-cell control of herpes zoster. Here, CD8A is linked to cytomegalovirus infection.