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Biology subjects

Moldenhauer, A.-S.

Publications and source records attributed to Moldenhauer, A.-S..

4 recordsLinked to original sources

Epidemiology and virological characteristics of the emerging SARS-CoV-2 variant PJ.2.1

SARS-CoV-2 continues to circulate globally at high levels and to evolve into new variants. Recently, a new saltation variant harbouring a highly mutated spike protein, PJ.2.1, emerged in North America. Here, we provide a brief epidemiological and virological characterization of PJ.2.1 and cocirculating variants. We report that PJ.2.1 is spreading in the USA, Canada, and Spain and mainly infects individuals aged 60 years and older, as do most other variants, with the exception of BA.3.2, which preferentially infects individuals aged 0-9 years. PJ.2.1 was less susceptible to inhibition by an antibody against ACE2 than were the other variants, indicating increased ACE2 binding. In contrast, PJ.2.1 did not show augmented evasion of antibodies from vaccinees who had received the LP.8.1-adapted vaccine compared with most other variants analysed. These results suggest that augmented ACE2 affinity rather than increased antibody evasion might drive the current, rapid spread of PJ.2.1.

microbiology↗

The Omicron variant is highly resistant against antibody-mediated neutralization - implications for control of the COVID-19 pandemic

The rapid spread of the SARS-CoV-2 Omicron variant suggests that the virus might become globally dominant. Further, the high number of mutations in the viral spike-protein raised concerns that the virus might evade antibodies induced by infection or vaccination. Here, we report that the Omicron spike was resistant against most therapeutic antibodies but remained susceptible to inhibition by Sotrovimab. Similarly, the Omicron spike evaded neutralization by antibodies from convalescent or BNT162b2-vaccinated individuals with 10- to 44-fold higher efficiency than the spike of the Delta variant. Neutralization of the Omicron spike by antibodies induced upon heterologous ChAdOx1/BNT162b2-vaccination or vaccination with three doses of BNT162b2 was more efficient, but the Omicron spike still evaded neutralization more efficiently than the Delta spike. These findings indicate that most therapeutic antibodies will be ineffective against the Omicron variant and that double immunization with BNT162b2 might not adequately protect against severe disease induced by this variant.

microbiology↗

Increased lung cell entry of B.1.617.2 and evasion of antibodies induced by infection and BNT162b2 vaccination

The delta variant of SARS-CoV-2, B.1.617.2, emerged in India and has subsequently spread to over 80 countries. B.1.617.2 rapidly replaced B.1.1.7 as the dominant virus in the United Kingdom, resulting in a steep increase in new infections, and a similar development is expected for other countries. Effective countermeasures require information on susceptibility of B.1.617.2 to control by antibodies elicited by vaccines and used for COVID-19 therapy. We show, using pseudotyping, that B.1.617.2 evades control by antibodies induced upon infection and BNT162b2 vaccination, although with lower efficiency as compared to B.1.351. Further, we found that B.1.617.2 is resistant against Bamlanivimab, a monoclonal antibody with emergency use authorization for COVID-19 therapy. Finally, we show increased Calu-3-lung cell entry and enhanced cell-to-cell fusion of B.1.617.2, which may contribute to augmented transmissibility and pathogenicity of this variant. These results identify B.1.617.2 as an immune evasion variant with increased capacity to enter and fuse lung cells.

molecular biology↗

SARS-CoV-2 variant B.1.617 is resistant to Bamlanivimab and evades antibodies induced by infection and vaccination

The emergence of SARS-CoV-2 variants threatens efforts to contain the COVID-19 pandemic. The number of COVID-19 cases and deaths in India has risen steeply in recent weeks and a novel SARS-CoV-2 variant, B.1.617, is believed to be responsible for many of these cases. The spike protein of B.1.617 harbors two mutations in the receptor binding domain, which interacts with the ACE2 receptor and constitutes the main target of neutralizing antibodies. Therefore, we analyzed whether B.1.617 is more adept in entering cells and/or evades antibody responses. B.1.617 entered two out of eight cell lines tested with slightly increased efficiency and was blocked by entry inhibitors. In contrast, B.1.617 was resistant against Bamlanivimab, an antibody used for COVID-19 treatment. Finally, B.1.617 evaded antibodies induced by infection or vaccination, although with moderate efficiency. Collectively, our study reveals that antibody evasion of B.1.617 may contribute to the rapid spread of this variant.

molecular biology↗