Comparison of neutralizing activity in trimer-immunized macaques and monomer-immunized humans. The ID₅₀ NAb titers in Env trimer-immunized macaques (NHPs; n = 16) and gp120 monomer-immunized humans participating in the VAX04 study (n = 20) were compared. The analysis was performed once, at multiple dilutions of each plasma sample. Plasmas were assayed against clade B Tier 1 viruses MN, HxBc2, SF162, and BaL.01 (top) and Tier 2 viruses YU2, 89.6, 6535, and ADA (middle), and against the clade A virus DJ263 (bottom left) and the clade C virus MW965 (bottom right). Significance was determined using ANOVA. ns = nonsignificant. ***, P ≤ 0.001.