Comparing the neutralization breadth of the three patient plasma in three variants of the PBMC assay, indicates that the HJ and HK plasma neutralize much fewer viruses and the HGN plasma even loses all significant neutralization capacity in the classical short assay (1/2/7), implying that none of them would have been selected using results from this assay. Prolonging the absorption phase to 24 hours (1/24/14), to more closely resemble the cell line based assays (see table 1), only ''rescues'' some neutralization with the HGN plasma. No correlation was found between the results obtained in the different PBMC assays using the Spearman Rank correlation test. There was a correlation between results from the 24/1/14 extended incubation PBMC assay and those with the TZMbl assay using replication competent ''primary'' viruses for the 242315-HJ plasma (r = 0.62, p = 0.03) but not for the other 2 plasma samples. A stronger correlation (r.0.60 for all three plasma) was found for the 242315 and 314994 plasma between the 24/1/14 PBMC assay and the TZMbl_PV assay. The correlation was statistically significant (p,0.04). The strongest correlation (r.0.69) was observed between the two PV assays (TZMbl-PV and GHOST_PV). Correlations for all three plasma were significant (p,0.01).