With regard to cell line based assays, there is a good concordance for HGN194 mAb and plasma in the GHOST-PV assay. Four of these HGN194-PV combinations are also neutralizing when the target cells are TZMbl. However, when infectious virus is used 10/12 combinations are enhancing. HJ16 mAb neutralizes 92RW009 and VI 1090 in all three cell-line assays while the corresponding plasma failed to do so in these assays (see Table 5 ). Remarkably, however, 92RW009 was neutralized by 242315-HJ plasma in the 1/2/7 PBMC assay selectively and VI 1090 was neutralized by HJ plasma in both the 24/1/14 and the 1/2/7 PBMC assay. The HK20 mAb only neutralizes VI 882 in the GHOST_PV assay, SF162 in the TZMbl_PV assay and does not neutralize any infectious virus. There was no consistent statistically significant correlation between the levels of neutralization reached in the 24/1/14 PBMC assay and the others except where only a few isolates were actually neutralized or neutralization levels were low.