Patient 242315 from whom the CD4bs specific HJ16 mAb was obtained was a 45 year old Congolese woman who had been visiting our clinic since 1996. She received treatment intermittently and consequently had a varying CD4 count and viral load. Her neutralization profile had been obtained using plasma samples taken after stopping anti-retroviral therapy for 6 to 11 months but she was back on therapy at time of memory B cell interrogation for 7 months. Patients 314994-HGN and 529552-HK were not receiving antiretroviral treatment during this study. Patient 314994 from whom the V3 crown specific mAb HGN194 was obtained was a 41 year old woman from the Republic of Guinea who has been regularly attending our clinic since 1998. She has always maintained low viral loads and high CD4 T counts so far without treatment. Her viral loads varied between undetectable and 2,700 RNA copies/ml while her CD4 counts have fluctuated between 550 and 960 cells/ml. Patient 529552 whose HK20 mAb is specific for the HR1 region of gp41 was a 31 year old Ghanaian woman. Soon after arrival in Belgium in 2005 she tested positive for HIV. Her viral loads (1.500-40.000 RNA copies/ml) have Table 2 ). In view of the known neutralization resistance of these isolates [6, 8] they were considered to represent 'Tier 2 like'' strains. In the experiments represented in Table 4 , an additional panel of four subtype B, four subtype D and four CRF01_AE strains provided us with an overview of the neutralizing potential of the three selected patient plasma across six subtypes with a total panel of 26 ''tier 2 like'' strains.