Ten emerging SARS-CoV-2 spike variants exhibit variable infectivity, animal tropism, and antibody neutralization

Emerging mutations in SARS-CoV-2 cause several waves of COVID-19 pandemic. Here we investigate the infectivity and antigenicity of ten emerging SARS-CoV-2 variants-B.1.1.298, B.1.1.7(Alpha), B.1.351(Beta), P.1(Gamma), P.2(Zeta), B.1.429(Epsilon), B.1.525(Eta), B.1.526-1(Iota), B.1.526-2(Iota), B.1.1.318-and seven corresponding single amino acid mutations in the receptor-binding domain using SARS-CoV-2 pseudovirus. The results indicate that the pseudovirus of most of the SARS-CoV-2 variants (except B.1.1.298) display slightly increased infectivity in human and monkey cell lines, especially B.1.351, B.1.525 and B.1.526 in Calu-3 cells. The K417N/T, N501Y, or E484K-carrying variants exhibit significantly increased abilities to infect mouse ACE2-overexpressing cells. The activities of furin, TMPRSS2, and cathepsin L are increased against most of the variants. RBD amino acid mutations comprising K417T/N, L452R, Y453F, S477N, E484K, and N501Y cause significant immune escape from 11 of 13 monoclonal antibodies. However, the resistance to neutralization by convalescent serum or vaccines elicited serum is mainly caused by the E484K mutation. The convalescent serum from B.1.1.7- and B.1.351-infected patients neutralized the variants themselves better than other SARS-CoV-2 variants. Our study provides insights regarding therapeutic antibodies and vaccines, and highlights the importance of E484K mutation. Li Zhang, Zhimin Cui, and Qianqian Li et al. compare the infectivity, host tropism, and antigenicity of 10 SARS-CoV-2 variants using a VSV-based pseudovirus system. Their results suggest that variants carrying E484K display the most significant reduction in sensitivity to neutralization, and may provide further insight into the development of relevant therapeutics for SARS-CoV-2 infection.

Automated summary

Most SARS-CoV-2 variants exhibit slightly increased infectivity in human and monkey cell lines, with certain variants showing enhanced infectivity in specific cell types. Variants carrying specific amino acid mutations demonstrate increased abilities to infect certain cell types. Some variants show resistance to neutralization by antibodies and vaccines, primarily due to the E484K mutation.