Chimeric spike mRNA vaccines protect against Sarbecoviru s challenge in mice

Figures

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  Figure 1.. Genetic design of chimeric Sarbecovirus spike vaccines. (A) Genetic diversity of pandemic and bat zoonotic coronaviruses. SARS-CoV is shown in light blue, RsSHC014 is shown in purple, and SARS-CoV-2 is shown in red. (B) Spike chimera 1 includes the NTD from HKU3–1, the RBD from SARS-CoV, and the rest of the spike from SARS-CoV-2. Spike chimera 2 includes the RBD from SARS-CoV-2 and the NTD and S2 from SARS-CoV. Spike chimera 3 includes the RBD from SARS-CoV and the NTD and S2 SARS-CoV-2. Spike chimera 4 includes the RBD from RsSHC014 and the rest of the spike from SARS-CoV-2. SARS-CoV-2 furin KO spike vaccine and is the norovirus capsid vaccine. (C) Table summary of chimeric spike constructs.

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  Figure 2.. Human pathogenic coronavirus spike binding and hACE2-blocking responses in chimeric and monovalent SARS-CoV-2 spike-vaccinated mice. Serum antibody ELISA binding responses were measured in the five different vaccination groups. Pre-immunization, post prime, and post-boost binding responses were evaluated against Sarbecoviruses, MERS-CoV, and common-cold CoV antigens including: (A) SARS-CoV Toronto Canada (Tor2) S2P, (B) SARS-CoV-2 S2P D614G, (C) SARS-CoV-2 RBD, (D) SARS-CoV-2 NTD, (E) Pangolin GXP4L spike, (F) RaTG13 spike, (G) RsSHC014 S2P spike, (H) HKU3–1 spike, (I) MERS-CoV spike, (J) hACE2 blocking responses against SARS-CoV-2 spike in the distinct immunization groups. Blue squares represent mice from group 1, orange triangles represent mice from group 2, green triangles represent mice from group 3, red rhombuses represent mice from group 4, and upside-down triangle represent mice from group 5. Statistical significance for the binding and blocking responses is reported from a Kruskal-Wallis test after Dunnett’s multiple comparison correction. *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001.

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  Figure 3.. Live Sarbecovirus neutralizing antibody responses in vaccinated mice. Neutralizing antibody responses in mice from the five different vaccination groups were measured using nanoluciferase-expressing recombinant viruses. (A) SARS-CoV neutralizing antibody responses from baseline and post boost in the distinct vaccine groups. (B) SARS-CoV-2 neutralizing antibody responses from baseline and post boost. (C) RsSHC014 neutralizing antibody responses from baseline and post boost. (D) WIV-1 neutralizing antibody responses from baseline and post boost. (E) The neutralization activity in groups 1 and 4 against SARS-CoV-2 D614G, South African B.1.351, U.K. B.1.1.7, and mink variants (F) Neutralization comparison of SARS-CoV-2 D614G vs. South African B.1.351, vs. U.K. B1.1.7, and mink variants. Statistical significance for the live-virus neutralizing antibody responses is reported from a Kruskal-Wallis test after Dunnett’s multiple comparison correction. *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001.

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  Figure 4.. In vivo protection against Sarbecovirus challenge after mRNA-LNP vaccination. (A) Percent starting weight from the different vaccine groups of mice challenged with SARS-CoV MA15. (B) SARS-CoV MA15 lung viral titers in mice from the distinct vaccine groups. (C) SARS-CoV MA15 nasal turbinate titers. (D) Percent starting weight from the different vaccine groups of mice challenged with SARS-CoV-2 MA10. (E) SARS-CoV-2 MA10 lung viral titers in mice from the distinct vaccine groups. (F) SARS-CoV-2 MA10 nasal turbinate titers. (G) Percent starting weight from the different vaccine groups of mice challenged with WIV-1. (H) WIV-1 lung viral titers in mice from the distinct vaccine groups. (I) WIV-1 nasal turbinate titers. (J) Percent starting weight from the different vaccine groups of mice challenged with SARS-CoV-2 B.1.351. (K) SARS-CoV-2 B.1.351 lung viral titers in mice from the distinct vaccine groups. (L) SARS-CoV-2 B.1.351 nasal turbinate titers. Figure legend at the bottom right depicts the vaccines utilized in the different groups. Statistical significance for weight loss is reported from a two-way ANOVA after Dunnett’s multiple comparison correction. For lung and nasal turbinate…

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  Figure 5.. Lung pathology in vaccinated mice after SARS-CoV and SARS-CoV-2 challenge. (A) Hematoxylin and eosin 4 days post infection lung analysis of SARS-CoV MA15 challenged mice from the different groups: group 1: chimeras 1–4 prime and boost, group 2: chimeras 1–2 prime and 3–4, group 3: chimera 4 prime and boost, SARS-CoV-2 furin KO prime and boost, and norovirus capsid prime and boost. (B) Lung pathology quantitation in SARS-CoV MA15 challenged mice from the different groups. Macroscopic lung discoloration score, microscopic acute lung injury (ALI) score, and diffuse alveolar damage (DAD) in day 4 post infection lung tissues are shown. (C) Hematoxylin and eosin 4 days post infection lung analysis of SARS-CoV-2 MA10 challenged mice from the different groups. (D) Lung pathology measurements in SARS-CoV-2 MA10 challenged mice from the different groups. Macroscopic lung discoloration score, microscopic acute lung injury (ALI) score, and diffuse alveolar damage (DAD) in day 4 post infection lung tissues are shown. Statistical significance is reported from a one-way ANOVA after Dunnet’s multiple comparison correction. *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001.