Determination of HIV-specific antibody neutralization breadth

Antibody neutralization was determined against a globally representative panel of 12 viruses belonging to subtypes A (n = 1), B (n = 2), C (n = 3), G (n = 1) and circulating recombinant forms (CRFs) (n = 5) [15,29]. Neutralization was measured as previously described [30–33] by a reduction in luciferase gene expression after single-round infection of TZM-bl cells with Env-pseudotyped viruses. Antibody potency was calculated as the plasma dilution needed to neutralize 50% viral infectivity, and breadth as the ability to neutralize more than 50% of this multisubtype panel.