Rapidly Emerging SARS-CoV-2 B.1.1.7 Sub-Lineage in the United States of America with Spike Protein D178H and Membrane Protein V70L Mutations

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Tag: variants

June 15, 2021

Rapidly Emerging SARS-CoV-2 B.1.1.7 Sub-Lineage in the United States of America with Spike Protein D178H and Membrane Protein V70L Mutations

Genomic surveillance of SARS-CoV-2 cases identified an expanding US-specific sub-lineage of the B.1.1.7 (Alpha) variant. This sub-lineage is characterized with sequential acquisition of a membrane protein mutation, V20L, in November 2020 and a spike mutation, D178H, in early February 2021. The proportion of B.1.1.7 (Alpha) isolates in the US belonging to this sub-lineage increased from…

June 11, 2021

BNT162b2-Elicited Neutralization of B.1.617 and Other SARS-CoV-2 Variants

An in-vitro study of sera from persons fully vaccinated with the Pfizer-BioNTech vaccine found that all samples neutralized SARS-CoV-2 virus variants B.1.617.1 (Kappa), B.1.617.2 (Delta), B.1.618 (first identified in India) and B.1.525 (Eta, first identified in Nigeria). Neutralization of all variants, with the exception of B.1.617.1, was only slightly reduced compared to neutralization of wild-type…

SARS-CoV2 Spike Protein Gene Variants with N501T and G142D Mutation-Dominated Infections in Mink in the United States

An analysis of SARS-CoV-2 sequences isolated from farmed mink populations (N=977) and human infections in the US and Canada (N=192,806) from December 2019-March 2021 revealed that the N501T mutation was found in humans two months prior to being detected in mink populations. However, in contrast to the N501Y mutation, which is present in the B.1.1.7…

June 10, 2021

Neutralizing Antibodies Elicited by the Ad26.COV2.S COVID-19 Vaccine Show Reduced Activity against 501Y.V2 (B.1.351) despite Protection against Severe Disease by This Variant

[Pre-print, not peer-reviewed] Anti-SARS-CoV-2 antibody binding responses among individuals 29 days after vaccination with the single-dose Johnson & Johnson-Janssen vaccine (n=88) were reduced by 1.8-fold against the B.1.351 (Beta) variant compared to the wild-type D614G strain. By contrast, 82% in a subset of 27 individuals showed no neutralizing activity against B.1.351 (Beta) at Day 29…

Second Generation Antibodies Neutralize Emerging SARS-CoV-2 Variants of Concern

[Pre-print, not peer-reviewed] AX290 and AX677 (AXON Neuroscience), second generation monoclonal antibodies developed specifically to target SARS-CoV-2 variants of concern, were experimentally shown to successfully neutralize the wild-type strain, B.1.1.7 (Alpha), and B.1.351 (Beta) in mouse models. Kovacech et al. (June 9, 2021). Second Generation Antibodies Neutralize Emerging SARS-CoV-2 Variants of Concern. Pre-print downloaded Jun 10…

Antibodies Elicited by mRNA-1273 Vaccination Bind More Broadly to the Receptor Binding Domain than Do Those from SARS-CoV-2 Infection

Vaccine-elicited anti-SARS-CoV-2 antibodies in individuals fully vaccinated with the Moderna vaccine in phase 1/2 trials (n=14) were found to target more epitopes within the receptor binding domain (RBD) when compared to individuals with prior infection. Binding of vaccine-elicited antibodies was more broadly distributed across epitopes compared to infection-elicited antibodies within the RBD, which the authors…

Immunogenicity of Ad26.COV2.S Vaccine against SARS-CoV-2 Variants in Humans

Median anti-SARS-CoV-2 neutralizing antibody titers of sera from individuals vaccinated with the Johnson & Johnson-Janssen vaccine in the phase 1/2 trials (n=20) were 5- and 3-fold lower against the B.1.351 (Beta) and P.1 (Gamma) variants, respectively, compared with the wild-type strain on day 71 following vaccination. Binding antibody titers were impaired but to a lesser…

Genomic Surveillance for SARS-CoV-2 Variants Circulating in the United States, December 2020–May 2021

During April 11-24, 2021, the SARS-CoV-2 B.1.1.7 (Alpha) variant accounted for an estimated 66% of US infections and the P.1 (Gamma) variant accounted for 5% of US infections, according to the CDC. Estimates are based on sequencing of 25,000 SARS-CoV-2-positive specimens, representing 3% of all reported positive tests and weighted to the general population. Estimated…

June 8, 2021

Neutralization against B.1.351 and B.1.617.2 with Sera of COVID-19 Recovered Cases and Vaccinees of BBV152

[Pre-print, not peer-reviewed] Sera from individuals fully vaccinated with the inactivated virus SARS-CoV-2 vaccine Covaxin (n=17) showed a 3-fold reduction in neutralizing activity against the B.1.351 (Beta) and B.1.617.2 (Delta) variants of concern compared with the parent D614G variant. Similarly, sera from individuals recovered from COVID-19 showed a 3-fold and 5-fold reduction in neutralizing activity…

Nanobodies from Camelid Mice and Llamas Neutralize SARS-CoV-2 Variants

Two groups of single-domain antibodies, known as nanobodies, isolated from llamas and genetically engineered mice was identified to possess anti-SARS-CoV-2 receptor binding domain (RBD) neutralizing activity. The first group is able to bind to a region in the RBD largely preserved across SARS-CoV-2 mutations but rarely targeted by human antibodies, while the second group demonstrated…