Broad neutralization against SARS-CoV-2 variants induced by a modified B.1.351 protein-based COVID-19 vaccine candidate

Su, D.; Li, X.; He, C.; Huang, X.; Chen, M.; Wang, Q.; Qin, W.; Liang, Y.; Xu, R.; Wu, J.; Luo, P.; Yang, X.; Zeng, Y.; Luo, M.; Luo, D.; Salisbury, D. M.; Ambrosino, D.; Siber, G.; Clemens, R.; Liang, P.; Liang, J. G.

doi:10.1101/2021.05.16.444369

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bioRxiv · 10.1101/2021.05.16.444369

Broad neutralization against SARS-CoV-2 variants induced by a modified B.1.351 protein-based COVID-19 vaccine candidate

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Abstract

Beginning in late 2020, the emergence and spread of multiple variant SARS-CoV-2 strains harboring mutations which may enable immune escape necessitates the rapid evaluation of second generation COVID-19 vaccines, with the goal of inducing optimized immune responses that are broadly protective. Here we demonstrate in a mouse immunogenicity study that two doses of a modified B.1.351 spike (S)-Trimer vaccine (B.1.351 S-Trimer) candidate can induce strong humoral immune responses that can broadly neutralize both the original SARS-CoV-2 strain (Wuhan-Hu-1) and Variants of Concern (VOCs), including the UK variant (B.1.1.7), South African variant (B.1.351) and Brazil variant (P.1). Furthermore, while immunization with two doses (prime-boost) of Prototype S-Trimer vaccine (based on the original SARS-CoV-2 strain) induced lower levels of cross-reactive neutralization against the B.1.351 variant, a third dose (booster) administered with either Prototype S-Trimer or B.1.351 S-Trimer was able to increase neutralizing antibody titers against B.1.351 to levels comparable to neutralizing antibody titers against the original strain elicited by two doses of Prototype S-Trimer.

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Su, D., Li, X., He, C., Huang, X., Chen, M., Wang, Q., Qin, W., Liang, Y., Xu, R., Wu, J., Luo, P., Yang, X., Zeng, Y., Luo, M., Luo, D., Salisbury, D. M., Ambrosino, D., Siber, G., Clemens, R., Liang, P., Liang, J. G.. 2021-05-17. Broad neutralization against SARS-CoV-2 variants induced by a modified B.1.351 protein-based COVID-19 vaccine candidate. https://doi.org/10.1101/2021.05.16.444369

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