IFNG and infection: Expression ratio of IFN-γ/TGF-β was increased in the pcDNA-HIS (p = 0.0003), and pcDNA-HIS/rHIS+CpG (p = 0.018) immunized groups compared with saline control suggesting that DNA-HIS immunized hamsters presented a pro-inflammatory immune response in the early stages of infection (Fig. 5B).