Fig. 1. Effect of adjuvants on trimer immunogenicity in rabbits.

a Schematic representation of the rabbit immunization schedule. Rabbits were immunized at weeks 0, 4, and 20 with ConM SOSIP.v7 trimer in the indicated adjuvants. Bleeds were taken at 0, 4, 6, 16, 20, and 22. Every color represents a specific adjuvant. The same color icons are used throughout all figures. b Midpoint serum-binding titers (EC₅₀) measured against ConM SOSIP.v7 trimer in ELISA. Differences between nonadjuvanted and the pooled adjuvanted groups were compared at each time point by the Mann–Whitney U test. c Midpoint serum-neutralization titers (ID₅₀) measured against ConM virus. Differences between nonadjuvanted and the pooled adjuvanted groups were compared at each time point by the Mann–Whitney U test. d Comparison of binding and neutralization titers two weeks after the second (week 6) and third immunization (week 22) from the pooled adjuvanted trimer group. A Wilcoxon test was used to determine differences. e Simple linear regression analysis of the midpoint binding titers and ConM neutralization titers over all postprime time points. The Spearman r values and p-values are indicated. f Comparison of the midpoint trimer binding titers between the adjuvanted trimer groups. g Comparison of the ConM neutralization titers between the different adjuvants. h Each individual ID₅₀ titer was normalized against the corresponding geometric mean ID₅₀ normalized to 1.0 (horizontal line). Shown are the pooled normalized ConM neutralization titers from all postprime time points. i Week 22 serum-neutralization titers against Tier 1B ConS virus and Tier 1 A SF162. Stars denote statistical differences: *p < 0.05; **p < 0.01; ***p < 0.001 determined by Kruskal–Wallis test, followed by Dunn’s post-test unless otherwise noted. (h) contains published data, see also Supplementary Table 2^11,56. All data were generated at the AMC. Horizontal lines represent geometric mean values.