In support of this, it has been shown that HCV infection is associated with a loss of other virus‐specific (CMV) mature effector memory CD8+ T cells.35 However, in the absence of liver cirrhosis, there is little evidence that HCV‐infected patients respond abnormally to routine clinical vaccines36; and in our study patients generated robust antivector T‐cell responses following vaccination. This evidence concerns the gene CD8A and cirrhosis of liver.