The emergence of SARS-CoV-2 variants has raised concerns about altered sensitivity to
antibody-mediated immunity. The relative resistance of SARS-CoV-2 variants B. 1.1. 7 and
B. 1.351 to antibody neutralization has been recently investigated. We report that another
emergent variant from Brazil, P. 1, is not only refractory to multiple neutralizing monoclonal
antibodies but also more resistant to neutralization by convalescent plasma and vaccinee
sera. The magnitude of resistance is greater for monoclonal antibodies than vaccinee sera …

A recently identified SARS-CoV-2 variant, Lambda, has spread to many countries around
the world. Here, we measured and evaluated the reduced sensitivity of Lambda variant to
the neutralization by plasma polyclonal antibodies elicited by the natural SARS-CoV-2
infection and inactivated vaccine. The combination of two substitutions appearing in the
RBD of spike protein (L452Q and F490S) resulted in noticeably reduced neutralization
against Lambda variant. F490S contributed more than L452Q in affecting the neutralization …