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[Preprint]. 2021 Sep 9:2021.03.26.437274. Originally published 2021 Mar 27. [Version 4] doi: 10.1101/2021.03.26.437274

Fig. 1. SApNP vaccines induce broadly neutralizing plasma responses to four representative SARS-CoV-2 variants.

Fig. 1.

(A) Molecular surface representations of two spike (S2PECTO-5GS-1TD0 and S2GΔHR2–5GS-1TD0) and three spike-SApNP (S2GΔHR2-5GS-ferritin [FR], S2GΔHR2-5GS-E2p-LD4-PADRE [E2p-L4P], and S2GΔHR2-10GS-I3-01v9-LD7-PADRE [I3-01v9-L7P]) vaccines. Representative EM image of S2GΔHR2-10GS-I3-01v9-L7P SApNPs is shown on the right. (B) Neutralization of the wildtype Wuhan-Hu-1 strain by mouse plasma induced by five different vaccines at week 5 after two intraperitoneal (i.p.) injections (n = 5 mice/group). ID50 titers derived from SARS-CoV-2-pp neutralization assays are plotted, with average ID50 values labeled on the plots. (C) Mouse plasma neutralization against Wuhan-Hu-1 and the B.1.1.7, B.1.351, P.1, and B.1.617Rec variants at week 5 after two i.p. injections of the adjuvanted S2GΔHR2-10GS-I3-01v9-L7P vaccine (Left panels 1–5: percent neutralization plots; Right panel: ID50 plot). In (B) and (C), the plasma samples were generated in our previous study (41), in which mice were immunized with 50 μg of adjuvanted vaccine antigen. (D) Neutralization of mouse plasma against the wildtype Wuhan-Hu-1 strain induced by the S2GΔHR2 spike and two large SApNPs at week 5. Vaccines were administered via intradermal (i.d.) footpad injections (0.8 μg/injection, for a total of 3.3 μg/mouse). (E) Mouse plasma neutralization against Wuhan-Hu-1 strain and the B.1.1.7, B.1.351, P.1, and B.1.617Rec variants at week 5 after two i.d. footpad injections. (F) Neutralization of mouse plasma against Wuhan-Hu-1 induced by the S2GΔHR2 spike and two large SApNPs at week 26. In (B)-(F), the ID50 values are plotted as mean ± SEM. The data were analyzed using one-way ANOVA for comparison between different vaccine groups or repeated measures ANOVA for comparison of ID50 titers from the same plasma sample against different SARS-Cov-2 strains. Dunnett’s multiple comparison post hoc test was performed. ns (not significant), **p < 0.01, ****p < 0.0001. (G) Neutralization of five SARS-CoV-2 strains by eight human monoclonal antibodies. The IC50 values were calculated with the % neutralization range constrained within 0.0–100.0% and color-coded (white: IC50 > 10 μg/ml; green to red: low to high).