Low neutralization of SARS-CoV-2 Omicron BA.2.75.2, BQ.1.1 and XBB.1 by parental mRNA vaccine or a BA.5 bivalent booster

Abstract

C.K. and J.Z. made equal contributions to the study.

Humoral responses against BQ.1.1 elicited after breakthrough infection and SARS-CoV-2 mRNA vaccination

“…For the BQ.1.1 S, at the M4-Va3 timepoint donors with recent BTI better recognized the S than individuals with no recent infection, and this difference in recognition was more significant four weeks after the fourth dose (Figure 1C). The level of BQ.1.1 S recognition was significantly lower compared to D614G S in donors without recent BTI (Figure 1D), in agreement with recent reports [4,5]. In donors who had recently been infected, there was a significant but smaller difference in the level of recognition between the two Spikes compared to the other group.…”

“…The results presented herein support these observations. As previously reported in numerous studies, including ours, hybrid immunity led to better humoral responses against the BQ.1.1 and other recent variants than just vaccination [4,5,32]. Also, we observed that after 4 doses of mRNA vaccine and no recent BTI, some donors did not have neutralizing activity against pseudoviral particles bearing the BQ.1.1 Spike.…”

“…Since its emergence in late 2021, the Omicron variant continues to evolve into new subvariants that are increasingly resistant to monoclonal antibodies and vaccination [5,[26][27][28][29][30]. To address vaccine resistance, bivalent mRNA vaccines, expressing both the original Spike and one of the parental lineages of Omicron (BA.1 or BA.4/5) Spike, have been developed and are now being administered in several jurisdictions worldwide.…”

“…The Omicron BQ.1.1 variant is a sublineage of the BA.5 variant that spreads very rapidly and is now the major circulating lineage in several countries [1,2]. Recent studies have shown that original SARS-CoV-2 mRNA vaccines, based on the ancestral Wuhan strain Spike (S), lead to poor humoral responses against several Omicron subvariants, including the BQ.1.1 variant [3][4][5]. With the goal to improve immune responses against these subvariants, Moderna and Pfizer bivalent vaccines have recently been approved by health authorities in many countries [6][7][8].…”

Mosaic Recombination Inflicted Various SARS-CoV-2 Lineages to Emerge into Novel Virus Variants: a Review Update

“…First time detected from the India, XBB recombinant variant has been derived from recombination between BJ.1 and BA.2.75. BJ.1 in turn is the result of recombination event between BM.1 and BM.XBB variant and is highly immune evasive strain leading to high chances of replacing the so far dominant BA.2.75 strain as also reported from national agency INSACOG which has confirmed 56% strain in India are XBB and soon going to replace the remaining 44% of BA.2.75 from India [ 43 – 45 ].…”