Fig. 3: Serum neutralizing activity following HIV-1 Env-CoPoP particle immunization.

a Color gradient map depicting the serum neutralizing activity of sera from week 18 blood draws against Env pseudotyped viruses with Murine Leukemia Virus (MLV) as negative control, a clade C panel and the global panel, measured in the TZM.bl neutralization assay. The tier and clade of each pseudovirus Env strain is shown in brackets. b Top left: scatter plot showing geometric mean titer (GMT) neutralization titers per rabbit within the Env-CoP1 (N = 9), Env-CoP2 (N = 9), Env-CoP3 (N = 8) and control (N = 4) groups, calculated as the GMT of serum neutralization against the n = 20 difficult-to-neutralize tier 2 HIV-1 strains used in panels. Top right: scatter plot showing neutralization breadth per rabbit, calculated as the % of strains neutralized out of the n = 20 tested tier 2 strains. Bottom: dot plot showing GMT neutralization vs. median % breadth for all groups in the study. Values below the neutralization assay lower limit of detection (LLOD) were set to 1/2 the LLOD of 10 serum ID₅₀ for plotting and analysis. Bars in left/middle graphs in b represent median with 95% confidence interval (CI) and the dotted lines represent the ELISA assay LLOD and numbers at the top of the graphs denote median values. c Neutralization fingerprint-based epitope prediction against major HIV-1 Env bNAb binding sites for week 18 sera. Numbers next to group allocation in a and c denote animal ID. Source data are provided as a Source Data file. bNAb: broadly neutralizing antibody; CD4bs: CD4 binding site; MPER: membrane proximal external region.