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bioRxiv2024

Neutralisation sensitivity of the SARS-CoV-2 BA.2.87.1 variant

Against the backdrop of the rapid global takeover and dominance of BA.1/BA.2 and subsequently BA.2.86 lineages, the emergence of a highly divergent SARS-CoV-2 variant warrants characterization and close monitoring. Recently, another such BA.2 descendent, designated BA.2.87.1, was detected in South Africa. Here, we show using spike-pseudotyped viruses that BA.2.87.1 is less resistant to neutralisation by prevailing antibody responses in Sweden than other currently circulating variants such as JN.1. Further we show that a monovalent XBB.1.5-adapted booster enhanced neutralising antibody titers to BA.2.87.1 by almost 4-fold. While BA.2.87.1 may not outcompete other currently-circulating lineages, the repeated emergence and transmission of highly diverged variants suggests that another large antigenic shift, similar to the replacement by Omicron, may be likely in the future.

immunology↗

bioRxiv2023

Humoral immune responses to the monovalent XBB.1.5-adapted BNT162b2 mRNA booster

Continued SARS-CoV-2 evolution and immune escape necessitated the development of updated vaccines, and a monovalent vaccine incorporating the XBB.1.5 variant spike protein is currently being rolled out. Amidst the emergence of the highly mutated BA.2.86 lineage and against the backdrop of pronounced immune imprinting, it is important to characterize the antibody responses following vaccination, particularly in the elderly. Here, we show that the monovalent XBB.1.5-adapted booster vaccination substantially enhanced both binding and neutralising antibody responses against a panel of variants, including BA.2.86, in an older population with four or more previous vaccine doses. Furthermore, neutralizing antibody titers to XBB.1.5 and BA.2.86 were boosted more strongly than titers to historical variants were. Our findings thereby suggest increased vaccine induced protection against both antigenically matched variants, as well as the more distant BA.2.86 variant, and support current vaccine policies recommending a monovalent XBB.1.5 booster dose to older individuals.

immunology↗