Neutralization of SARS-CoV-2 Variants by mRNA and Adenoviral Vector Vaccine-Elicited Antibodies

Figures

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  Figure 1. Comparison of neutralization titers of variant spike protein pseudotyped viruses by convalescent sera, antibodies elicited by BNT162b2, mRNA-1273, Ad26.COV2.S. (A) Neutralization of variant spike protein pseudotyped viruses by convalescent serum (n = 8) (left). Neutralizing titers of serum samples from BNT162b2 vaccinated individuals (n = 15) (middle). Neutralizing titers of serum samples from mRNA-1273 vaccinated donors (n = 6) (right). The serum was collected at early time point (7 days after second immunization). Serum samples from Ad26.COV2.S vaccinated donors were not available. The neutralization IC50 from individual donors is shown. Significance is based on two-sided t-test. Units on the Y axis of the graph for convalescent serum samples has been adjusted to allow for visualization of the data. (B) Comparison of neutralization of variants by convalescent serum (n = 8, the same donors in A), BNT162b2 vaccinated individuals (n = 9), mRNA-1273 vaccinated donors (n = 8), Ad26.COV2.S vaccinated donors (n = 10), sera from vaccinated individuals were collected at later time points [Day 52-110 (mean 90), Day 44-105 (mean 80), Day 57-115 (mean 82 days) after last immunization of…

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  Figure 2. Neutralization of variant spike protein pseudotyped viruses by Regeneron antibodies. Neutralization of Beta, Delta, Delta plus and Lambda variant spike protein variants by REGN10933 and REGN10987 monoclonal antibodies. Neutralization of D614G and variant pseudotyped viruses by REGN10933 (left), REGN10987 (middle), and 1:1 ratio of REGN10933 and REGN10987 (right). The IC50 values of REGN10933, REGN10987 and the cocktail is shown in the table.

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  Figure 3. Neutralization of variant spike protein pseudotyped viruses by sACE2, monoclonal antibodies and virus-ACE2 binding assay. (A) Infectivity of virus pseudotyped by variant and D614G spike proteins. Viruses were normalized for RT activity and applied to target cells. Infectivity of viruses pseudotyped with the variant spike proteins were tested on ACE2.293T. Luciferase activity was measured two days post-infection. Significance was based on two-sided t-test. (B) Neutralization of variant spike protein variants by sACE2. Viruses pseudotyped with variant spike proteins were incubated with a serially diluted recombinant sACE2 and then applied to ACE2.293T cells. Each plot represents the percent infectivity of D614G and other variant spike pseudotyped viruses. The diagram shows the IC50 for each curve. (C) Nickel beads were coated for 1 hour with 1, 0.5 and 0.1 μg of sACE2 proteins. Unbound protein was removed and SARS-CoV-2 variant pseudotyped virions (D614G, Alpha, Beta, Delta, Lambda) were incubated with the beads. After 1 hour, the bound virions were analyzed on an immunoblot with antibody p24 antibody. Beads-bound p24 (ng) was calculated and indicated in the bottom (left). Input…