However, neutralization of the Brazilian/Japanese P.2 variant, whose RBD contains an E484K mutation, was significantly decreased (5.8-fold for BNT162b2, 0.001; 2.9-fold for mRNA-1273, 0.01) (Figure 4CCD and S4A). indicates identical neutralization, and the dotted diagonal black lines indicate a 10-fold difference in pseudovirus neutralization (pNT50). Four groups of vaccine recipients are indicated: (= 22, blue circles); (= 7, light blue triangles); (= 4, red squares); and (= 14, pink diamonds). (B) Surface expression of the indicated variant spike proteins on the surface of transfected 293T cells was measured by flow cytometry. Transfected cells were stained with three monoclonal antibodies targeting spike, S309, ADI-55689, and ADI-56046, and median fluorescence AMD 070 intensities (MFI) of transfected (GFP+) cells were averaged to obtain a relative MFI demonstrating efficient expression of all AMD 070 spikes at the cell surface. Bars and error bars indicate mean and standard deviation. Rabbit polyclonal to ITLN2 (C) To determine the consistency of pseudovirus neutralization titers (pNT50) measured by this assay, varying amounts of infectious units per well of wild-type SARS-CoV-2 and B.1.351 v1 pseudovirus were used to perform the neutralization assay for 22 serum samples from BNT162b2 vaccine recipients 7 days out from their second dose. These data demonstrate the robustness of calculating pNT50 across a 22-fold range of infectious units of pseudovirus. NIHPP2021.02.14.21251704-supplement-1.pdf (7.1M) GUID:?082EE79E-A68A-41EF-ADF8-C4E46E969E13 Data Availability StatementThis study did not generate sequence data or code. Data generated in the current study (including ELISA and neutralization) have not been deposited in a public repository but are available from the corresponding author upon request. SUMMARY Vaccination elicits immune responses capable of potently neutralizing SARS-CoV-2. However, ongoing surveillance has revealed the emergence of variants harboring mutations in spike, the main target of neutralizing antibodies. To understand the impact of these variants, we evaluated the neutralization potency of 99 individuals that received one or two doses of either BNT162b2 or mRNA-1273 vaccines against pseudoviruses representing 10 globally circulating strains of SARS-CoV-2. Five of the 10 pseudoviruses, harboring receptor-binding domain mutations, including K417N/T, E484K, and N501Y, were AMD 070 highly resistant to neutralization. Crossneutralization of B.1.351 variants was comparable to SARS-CoV and bat-derived WIV1-CoV, suggesting that AMD 070 a relatively small number of mutations can mediate potent escape from vaccine responses. While the clinical impact of neutralization resistance remains uncertain, these results highlight the potential for variants to escape from neutralizing humoral immunity and emphasize the need to develop broadly protective interventions against the evolving pandemic. selection experiments to escape from monoclonal antibodies (Baum et al. 2020) and was also recently identified through deep mutational scanning as a variant with the potential to evade monoclonal and serum antibody responses (Greaney et al. 2020, 2021). Novel variants arising from the B.1.1.28 lineage first described in Brazil and Japan, termed P.2 (with 3 spike missense mutations) and P.1 (with 12 spike missense mutations), contain this E484K mutation, and P.1 in particular also contains K417T and N501Y mutations in RBD. These strains have been spreading rapidly, and both P.2 and P.1 were recently found in documented cases of SARS-CoV-2 re-infection (Paiva et al. 2020; Faria et al. 2021; Resende et al. 2021; Naveca et al. 2021; Nonaka et al. 2021). Of greatest concern has been the emergence of multiple strains of the B.1.351 lineage (also known as 501Y.V2), which were first reported in South Africa and have since spread globally (Tegally et al. 2021). This lineage bears three RBD mutations, K417N, E484K, and N501Y, in addition.