The rapid rise of SARS-CoV-2 Omicron subvariants with immune evasion properties: XBB.1.5 and BQ.1.1 subvariants

Abstract

As the fifth variant of concern of the SARS-CoV-2 virus, the Omicron variant (B.1.1.529) has quickly become the dominant type among the previous circulating variants worldwide. During the Omicron wave, several subvariants have emerged, with some exhibiting greater infectivity and immune evasion, accounting for their fast spread across many countries. Recently, two Omicron subvariants, BQ.1 and XBB lineages, including BQ.1.1, XBB.1, and XBB.1.5, have become a global public health issue given their ability to escape from therapeutic monoclonal antibodies and herd immunity induced by prior coronavirus disease 2019 (COVID-19) vaccines, boosters, and infection. In this respect, XBB.1.5, which has been established to harbor a rare mutation F486P, demonstrates superior transmissibility and immune escape ability compared to other subvariants and has emerged as the dominant strain in several countries. This review provides a comprehensive overview of the epidemiological features, spike mutations, and immune evasion of BQ.1 and XBB lineages. We expounded on the mechanisms underlying mutations and immune escape from neutralizing antibodies from vaccinated or convalescent COVID-19 individuals and therapeutic monoclonal antibodies (mAbs) and proposed strategies for prevention against BQ.1 and XBB sublineages.

Keywords: BQ.1 and XBB lineages; Omicron; XBB.1.5; immune escape.

FIGURE 1

The estimated proportions of BQ.1 and XBB lineages. (A) and (B) show the proportions of the Omicron subvariants and other variants that moved every two weeks from 15 September, 2022 to 2 February, 2023 globally and in other three countries (Singapore, USA and UK). Data were obtained from GISAID and last accessed on 2 February 2023. (C) shows the global Re of BA.5, BQ.1, BQ.1.1, XBB, XBB.1 and XBB.1.5.

FIGURE 2

Schematic diagram shows the spike mutations of BQ.1 (A) and XBB lineages (B), including their ancestral strains BA.5 and BA.2. The mutations of BA.2, BA.5, BQ.1, and XBB are obtained from Refs. [3, 8, 59], and last accessed on 20 January 2023.

FIGURE 3

The superior transmissibility of BQ.1 and XBB lineages. New subvariants of the Omicron variant, BQ.1/BQ.1.1 and XBB/XBB.1/XBB.1.5, with substantial mutations, have contributed to the advantage in immune evasion and sharp increase in infectivity.