(A) The humoral response of vaccinated NHPs was profiled against several SARS-CoV-2 spike proteins (Spike: D614G, N501YΔ69–70, and E484K). The antibody titers and FcR binding titers were assayed by Luminex and the functional responses were analyzed using their respective assays. The bars represent the median response and error bars represent standard deviation. (B) The dot plots show the correlation of the IgG1 titer, FcRgIIA-I binding titer, ADCP, or complement deposition between D614G SARS-CoV-2 and the variants N501YΔ69–70 and E484K. D614G is plotted as an example of perfect correlation. A 2-way ANOVA with Tukey correction for multiple comparisons was used to compare antibody levels between groups. Only significant comparisons are shown. ns, not significant, *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001, ****p ≤ 0.0001. This figure can be generated from the data found in data/figure7_data.csv of https://github.com/dzhu8/Ad26-Dose-Down. ADCP, antibody-dependent cellular phagocytosis; FcR, Fcγ receptor; MFI, median fluorescent intensity; NHP, nonhuman primate; SARS-CoV-2, Severe Acute Respiratory Syndrome Coronavirus 2; VOC, variant of concern.