Extended Data Figure 5. Dose-dependent mRNA-1273-elicited antibody responses reveal strong positive correlation between binding and pseudovirus neutralization titers.

BALB/cJ mice (n=10/group) were immunized at weeks 0 and 3 weeks with various doses (0.0025 – 20 μg) of mRNA-1273. Sera were collected 2 weeks post-boost and assessed for SARS-CoV-2 S-specific IgG by ELISA (a) and neutralizing antibodies against homotypic SARS-CoV-2 pseudovirus (b). (a-b) All doses were compared to the 20 μg dose by two-sided Mann-Whitney test in a stepwise fashion, such that lowest doses were tested first at α = 0.05 and higher doses tested only if the lower doses were significant. Data are presented as GMT +/− geometric SD, and dotted lines represent assay limits of detection. (c) Spearman correlation test was used to correlate binding antibody titers to pseudovirus neutralizing antibody titers (p < 0.0001). Each dot represents an individual mouse. Dotted lines highlight log₁₀ IC₅₀ boundaries. ** = p-value < 0.01, *** = p-value < 0.001.