In order to determine if the hexon-modified vectors were presenting the MPER epitope within the hexon region, purified unmodified Ad5, Ad5/HVR2-MPER-L15(Gag), or Ad5/HVR2-MPER-L15DE1 were subjected to Western blot analysis with anti-gp41 antibody. The MPER protein was detected as a 119 KDa protein band associated with Ad5/HVR2-MPER-L15(Gag) or Ad5/ HVR2-MPER-L15DE1 particles, Figure 2 -B, lanes 2 and 3, respectively. The size of the 119 KDa band corresponds to the expected size of the Ad5 hexon protein with MPER peptide genetically incorporated into the HVR2 region. There was no MPER protein detected on Ad5 wild type particles (Figure 2-B, lane 1) .