Antigenicity assessment of SARS-CoV-2 saltation variant BA.2.87.1

Abstract

The recent emergence of a SARS-CoV-2 saltation variant, BA.2.87.1, which features 65 spike mutations relative to BA.2, has attracted worldwide attention. In this study, we elucidate the antigenic characteristics and immune evasion capability of BA.2.87.1. Our findings reveal that BA.2.87.1 is more susceptible to XBB-induced humoral immunity compared to JN.1. Notably, BA.2.87.1 lacks critical escaping mutations in the receptor binding domain (RBD) thus allowing various classes of neutralizing antibodies (NAbs) that were escaped by XBB or BA.2.86 subvariants to neutralize BA.2.87.1, although the deletions in the N-terminal domain (NTD), specifically 15-23del and 136-146del, compensate for the resistance to humoral immunity. Interestingly, several neutralizing antibody drugs have been found to restore their efficacy against BA.2.87.1, including SA58, REGN-10933 and COV2-2196. Hence, our results suggest that BA.2.87.1 may not become widespread until it acquires multiple RBD mutations to achieve sufficient immune evasion comparable to that of JN.1.

SARS-CoV-2 omicron BA.2.87.1 exhibits higher susceptibility to serum neutralization than EG.5.1 and JN.1

“…In summary, our findings suggest that the Omicron subvariant BA.2.87.1 is less immune-evasive and does not demonstrate more substantial engagement with viral receptor or infectivity compared to EG.5.1 and JN.1. Our observations are in line with results reported by Zhang et al using sera from participants from Germany [ 6 ]; by Lasrado et al using sera from participants in the US [ 7 ]; and by Yang et al, using sera from participants in China [ 8 ]. Yet, they contrast with the findings of Wang et al using sera from participants from China [ 9 ].…”

COVID-19 Serum Drives Spike-Mediated SARS-CoV-2 Variation

“…Nevertheless, introducing the S813I mutation to DV1 (forming DV4) subtly reduced neutralization susceptibility by 1.3-to 1.6-fold compared to the WT strain (Figure 2C,D). Interestingly, both the Beta variant and the recently emerged BA.2.87.1 variant carry the D215 mutation, with the latter's resistance to humoral immunity attributed to two deletions (∆15-26 and ∆136-146) in the NTD [21,22]. These observations highlight the necessity of monitoring mutations within the NTD as well as the RBD.…”