Serum neutralization of SARS-CoV-2 Omicron BA.2, BA.2.75, BA.2.76, BA.5, BF.7, BQ.1.1 and XBB.1.5 in individuals receiving Evusheld (preprint)

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant is undergoing continuous evolution and convergent mutation, which has led to the rapid emergence of several new variants. These new subvariants carry different mutations in theirreceptor-binding domain (RBD), raising concerns that they may evade neutralizing monoclonal antibodies (mAbs). In this study, we investigated the serum neutralization efficacy of Evusheld (cilgavimab and tixagevimab) antibody cocktails against SARS-CoV-2 Omicron sublineages BA.2, BA.2.75, BA.2.76, BA.5, BF.7, BQ.1.1 and XBB.1.5. Our results show that Evusheld retained neutralizing activity against BA.2, BA.2.75 and BA.5, albeit with somewhat reduced titers. However, the neutralizing activity of Evusheld against BA.2.76, BF.7, BQ.1.1 and XBB.1.5 significantly decreased, with XBB.1.5 showing the greatest escape activity among the subvariants, followed by BQ.1.1, BA.2.76 and BF.7. We also observed that recipients of Evusheld displayed elevated antibody levels in their serum, which efficiently neutralized the original variant, and exhibited different characteristics of infection than those who did not receive Evusheld. These findings provide important guidance for the application of Evusheld in treating SARS-CoV-2 subvariant infections.