Immune escape of BA.2.86 is comparable to XBB subvariants from the plasma of BA.5‐ and BA.5‐XBB‐convalescent subpopulations

Abstract

The EG.5.1 variant of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) has been prevalent since mid‐July 2023 in the United States and China. The variant BA.2.86 has become a major concern because it is 34 mutations away from the parental variant BA.2 and >30 mutations from XBB.1.5. There is an urgent need to evaluate whether the immunity of the population and current vaccines are protective against EG.5.1 and BA.2.86. Based on a cohort of two breakthrough‐infected groups, the levels of neutralizing antibodies (NAbs) against different subvariants were measured using pseudovirus‐based neutralization assays. XBB.1.5, EG.5.1, and BA.2.86 are comparably immune‐evasive from neutralization by the plasma of individuals recovered from BA.5 infection (BA.5‐convalescent) or XBB.1.9.2/XBB.1.5 infection following BA.5 infection (BA.5‐XBB‐convalescent). NAb levels against EG.5.1 and BA.2.86 subvariants remained >120 geometric mean titers (GMTs) in BA.5‐XBB‐convalescent individuals 2 months postinfection but were <40 GMTs in BA.5‐convalescent individuals. Furthermore, the XBB‐targeting messenger RNA (mRNA) vaccine RQ3033 induced higher levels of NAbs against XBB.1.5, EG.5.1, and BA.2.86 than against BA.5‐XBB infection. The results suggest that BA.2.86 and EG.5.1 are unlikely to cause more severe concerns than the currently circulating XBB subvariants and that the XBB.1.5‐targeting mRNA vaccine tested has promising protection against EG.5.1 and BA.2.86.

Robust Neutralization of SARS-CoV-2 Variants Including JN.1 and BA.2.87.1 by Trivalent XBB Vaccine-Induced Antibodies

“…From December 2022 to January 2023, over 80% of China’s population experienced BA.5/BF.7 infections despite receiving three doses of inactivated vaccines. Subsequently, from May to July 2023, approximately one-fifth of the population was affected by the XBB wave 7,8 . It is critical to assess whether the immunity in these subpopulations from XBB reinfection remains protective.…”