Figure 1: Viral Evolution in an Animal with no Known Protective Mamu Alleles. (a) Comparison of Vif-specific IFN- 𝛾 ELISPOT values for the vaccinated Mamu-A* 0 1 , - 𝐵 0 8 , - 𝐵 1 7 SP animal 16044 before and after an observed Vif YFPCFTAGEVR to YFPCFAAGEVR mutation. Statistical analysis was performed using the Mann Whitney test. (b) NASBA viral loads and ELISPOT results for acute (Vif) and chronic (Gag) epitopes were compared to determine the ability of CTLs targeting either the Gag or Vif epitope to control viral replication.