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bioRxiv · 10.1101/2024.10.23.619754

Enhanced immune evasion of SARS-CoV-2 KP.3.1.1 and XEC through NTD glycosylation

Liu, J.·Yu, Y.·Jian, F.·Yang, S.·Song, W.·Wang, P.·Yu, L.·Shao, F.·Cao, Y.
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Abstract

KP.3.1.1 has surpassed KP.3 to become the new globally dominant strain, while XEC, a recombinant variant of KS.1.1/KP.3.3, is rapidly expanding across Europe and North America. Notably, both variants carry mutations, S31del of KP.3.1.1 and T22N of XEC, that could introduce new N-linked glycans on the Spike N-terminal domain (NTD), emphasizing the urgent need to assess their potential changes in viral characteristics. Here, we found that both KP.3.1.1 and XEC maintained the high ACE2-Spike binding affinity and pseudovirus infectivity of KP.3. Importantly, compared to KP.3, KP.3.1.1, and especially XEC, could further evade the neutralizing antibodies in convalescent plasma, even those elicited by KP.2-like breakthrough infections. Interestingly, both variants demonstrated increased resistance against monoclonal neutralizing antibodies targeting various epitopes on the receptor-binding domain (RBD). These suggest that the additional NTD glycosylation of KP.3.1.1 and XEC could enhance immune evasion via allosteric effects, and supports the future prevalence of XEC.

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Liu, J., Yu, Y., Jian, F., Yang, S., Song, W., Wang, P., Yu, L., Shao, F., Cao, Y.. 2024-10-23. Enhanced immune evasion of SARS-CoV-2 KP.3.1.1 and XEC through NTD glycosylation. https://doi.org/10.1101/2024.10.23.619754

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