The capacity of convalescent and vaccine-elicited sera and monoclonal antibodies (mAb) to neutralize SARS-CoV-2 variants is currently of high relevance to assess the protection against infections. We performed a cell culture-based neutralization assay focusing on authentic SARS-CoV-2 variants B.1.617.1 (Kappa), B.1.617.2 (Delta), B.1.427/B.1.429 (Epsilon), all harboring the spike substitution L452R. We found that authentic SARS-CoV-2 variants harboring L452R had reduced susceptibility to convalescent and vaccine-elicited sera and mAbs. Compared to B.1, Kappa and Delta showed a reduced neutralization by convalescent sera by a factor of 8.00 and 5.33, respectively, which constitutes a 2-fold greater reduction when compared to Epsilon. BNT2b2 and mRNA1273 vaccine-elicited sera were less effective against Kappa, Delta, and Epsilon compared to B.1. No difference was observed between Kappa and Delta towards vaccine-elicited sera, whereas convalescent sera were 1.51-fold less effective against Delta, respectively. Both B.1.617 variants Kappa (+E484Q) and Delta (+T478K) were less susceptible to either casirivimab or imdevimab. In conclusion, in contrast to the parallel circulating Kappa variant, the neutralization efficiency of convalescent and vaccine-elicited sera against Delta was moderately reduced. Delta was resistant to imdevimab, which, however, might be circumvented by combination therapy with casirivimab together.
【저자키워드】 SARS-CoV-2, Corona virus, vaccination, Delta, B.1.617.2, monoclonal antibodies, Kappa, Epsilon, B.1.617.1, BNT2b2, mRNA1273, 【초록키워드】 neutralization, susceptibility, monoclonal antibody, variant, SARS-CoV-2 variant, combination therapy, monoclonal antibodies, infections, SARS-CoV-2 variants, Neutralization assay, Casirivimab, Imdevimab, L452R, Epsilon, mRNA1273, sera, B.1.617, Cell culture, convalescent, convalescent sera, mAbs, mAb, B.1, Efficiency, reduction, T478K, Factor, no difference, circulating, susceptible, effective, Cell, neutralize, greater, performed, reduced, less, 【제목키워드】 B.1.617,