IFNA1 and infection: The effect of therapy on HCV-specific T cell responses has been an area of investigation and controversy for some years in genotype-1 infection but is unexplored in genotype-3a infection with the exception of one study suggesting that proliferative responses to NS3 are enhanced in genotype-3 infection during treatment.40 How exactly therapy impacts on anti-viral T cell responses is complicated by the fact that IFN has both direct antiviral and also a broad range of immunomodulatory properties.