The mAbs were generated using cellular techniques as previously described [66] . Briefly, peripheral blood mononuclear cells (PBMCs) were EBV transformed in 96-well plates and cultured with a polyclonal B cell activator, CpG [67] , which enhanced EBV infection and B cell transformation. The wells containing Ab-producing cells were identified by testing the culture supernatants for binding activity to V3C-CTB [47] . Cells from wells that test positive were expanded and fused with the heteromyeloma cell line SHM-D33 (ATCC; catalog no. 1668). The fused cells that continued to make functional Abs were repeatedly cloned until monoclonality was achieved. The Abs were purified from culture supernatants using Protein G affinity columns (GE Healthcare) and concentration of the mAbs was determined by noncommercial ELISA. The anti-V3 mAb 447-52D generated previously from a clade B infected individual and a mAb 1418, specific to parvovirus B19 [68] , were used as control Abs in this study.