The mixtures were then transferred to 96-well, cell culture-treated, flat-bottom microplate containing confluent Vero cell monolayers in duplicate and incubated for further 2?hr, followed by the addition of 1 1.5% semi-solid carboxymethyl cellulose (CMC) overlay medium to each well to limit virus diffusion. the ACE2 interacting surface. We examine Edoxaban the ability of B.1.1.7 to evade antibody responses elicited by natural SARS-CoV-2 contamination or vaccination. We map the impact of N501Y by structure/function analysis of a large panel of well-characterized monoclonal antibodies. B.1.1.7 is harder to neutralize than parental computer virus, compromising neutralization by some members of a major class of public antibodies through light-chain contacts with residue 501. However, widespread escape from monoclonal antibodies or antibody responses generated by natural contamination or vaccination was not observed. Keywords: SARS-CoV-2, B.1.1.7, Kent, variant, antibody, escape, neutralization, IGHV3-53 Graphical abstract Open in a separate window Highlights ? Initial strain convalescent and vaccine sera show reduced B.1.1.7 neutralization ? N501Y enhances RBD: ACE2 binding affinity ? N501Y compromises neutralization by many antibodies with public V-region IGHV3-53 ? LEG8 antibody No widespread escape by B.1.1.7 was observed The SARS-CoV-2 B.1.1.7 variant is not neutralized as easily as the original form of the computer virus. Some public antibodies cannot neutralize B.1.1.7, due to altered light-chain contacts with residue 501. However, B.1.1.7 does not show widespread escape from monoclonal antibodies, natural antibody responses, or vaccines. Introduction Since its first appearance in Wuhan in December 2019, SARS-CoV-2 rapidly spread around the world leading the WHO to declare a pandemic on March 11, 2020. Since then, drastic public health steps, including draconian lockdowns with severe economic cost, have been enacted to contain computer virus spread. Although initially successful at made up of disease, many countries are now experiencing further waves of contamination, coinciding with winter in the northern hemisphere, with infections in some countries outpacing those seen during the first wave (Kr?ger and Schlickeiser, 2021). Huge strides have been made in the understanding of SARS-CoV-2 over the last 12 months, which are exemplified by the licensing of several vaccines (in the UK those made by Pfizer-BioNtech, Moderna, and Oxford-AstraZeneca), which are being rolled out?in massive global vaccination programs, with the aim to reach billions of individuals in 2021. Furthermore, Janssen and?Novavax have recently reported results showing good efficacy and also report efficacy against the UK B.1.1.7 strain (https://blogs.sciencemag.org/pipeline/archives/2021/01/29/jj-and-novavax-data). In parallel, a number of potently neutralizing monoclonal antibodies (mAbs) have been developed that are in late-stage trials to be used prophylactically or therapeutically (Baum et?al., 2020, Yang et?al., 2020). SARS-CoV-2 is usually a large positive-stranded RNA computer virus; the major virion surface glycoprotein is the trimeric spike that attaches the computer virus to host cells via the ACE2 receptor and, through a series of conformational changes, allows fusion of host and virion membranes releasing the computer virus RNA into the cell to start the infection cycle (Hoffmann et?al., Edoxaban 2020; Ou et?al., 2020). Spike is the target of RNA (Polack et?al., 2020; Baden et?al., 2021), viral vectored (Voysey et?al., 2021), and inactivated computer virus and recombinant protein-based vaccines (Yadav et?al., 2020). Because of the huge number of genome replications that occur in infected populations and error-prone replication, viral mutations do and will continue to occur (Robson et?al., 2020). Although the vast majority will be inconsequential or detrimental to viral fitness, a few may give the computer virus a Edoxaban competitive advantage and be the subject of rapid natural selection relating to transmission advantage, including enhanced replication and immune evasion. This leads to the emergence of dominant new variant viruses. Coronaviruses, as Edoxaban we are seeing with COVID-19, have the potential to alter their proteins with dramatic effect (Denison et?al., 2011). In recent months, a number of mutations in the spike protein have been exemplified by viruses that have produced in option hosts such as mink and transmitted back to humans or in immunocompromised chronically infected individuals (Kemp et?al., 2020; Oude Munnink et?al., 2021; Hayashi et?al., 2020). While most of these mutations currently show little.