Figure 1.
mRNA-1273 elicits SARS-CoV-2 binding and neutralizing antibodies
(A–D) Sera were collected at weeks 6, 24 or 25, and 48 post-immunization and days 2, 4, 7, and 14 post-challenge. IgG binding titers to (A) WA1 S-2P, (B) WA1 RBD, (C) B.1.617.2 RBD, and (D) B.1.351 RBD. IgG-binding titers in (A) are expressed in WHO units. Circles in (A)–(D) indicate individual NHPs. Boxes represent interquartile range with the median denoted by a horizontal line. 4–8 NHPs per group. Dotted lines in (A)–(D) are for visualization purposes and denote 1-log10 (A) or 4-log10 (B–D) increases in binding titers. Statistical analysis shown for mRNA-1273 cohort only.
(E) Sera were collected at weeks 6, 24, and 48 post-immunization. Neutralizing antibody titers assessed from a live virus assay with D614G, P.1, B.1.351, and B.1.617.2. Circles indicate GMTs, and error bars represent 95% confidence interval (CI). Values above circles represent fold reduction in GMTs for each variant in comparison to D614G at each time point. Dotted line indicates assay limit of detection. 8 NHPs per group. Statistical analysis shown for variant-specific responses at weeks 24 and 48 in comparison to corresponding variant-specific responses at preceding time point.
(F and G) Sera were collected at weeks 6, 24, and 48 post-immunization and days 2, 4, 7, and 14 post-challenge. Neutralizing antibody titers assessed from a lentiviral pseudovirus assay with either D614G or B.1.617.2 S. 4–8 NHPs per group.
(F) Light red lines and symbols indicate individual NHPs, while dark red lines and symbols indicate GMTs. Values above symbols represent fold reduction in neutralizing titers to B.1.617.2 compared with D614G at each time point. Dotted line indicates assay limit of detection. Statistical analysis shown for neutralizing titers to B.1.617.2 in comparison with D614G at each time point.
(G) Circles indicate GMTs, and error bars represent 95% CI. Dotted line indicates assay limit of detection. Statistical analysis shown for variant-specific responses at weeks 24 and 48 in comparison to corresponding variant-specific responses at preceding time point.
(H) Sera were collected at weeks 6, 24, and 48 post-immunization to determine anti-WA1 S-2P IgG avidity index. Circles indicate GMTs, and error bars represent 95% CI. Statistical analysis shown for avidity at weeks 24 and 48 in comparison to avidity at preceding time point. 8 NHPs per group.