Contradictorily, the increased number of Tregs and increased expression of FoxP3 and other effector molecules can interfere with the antiviral response of immune cells such as cytotoxic T cells (CD8+) in the severe phase of the infection [80] [Figure 3] as compared to the initial phase of the infection which in turn can lead to the secondary re-expansion of disease [20,79,81]. Here, CD8A is linked to infection.