Omicron neutralisation: RBD-dimer booster versus BF.7 and BA.5.2 breakthrough infection

• Published in: The Lancet (British edition) Vol. 402; no. 10403; pp. 687 - 689
• Main Authors: Dai, Lianpan, Duan, Huixin, Liu, Xueyuan, Zhou, Huan, Duan, Minrun, An, Yaling, Yuan, Linfeng, Zhao, Xin, Xu, Kun, Wu, Qiang, Gao, George F
• Format: Journal Article
• Language: English
• Published: London Elsevier Limited 26.08.2023
• Subjects: Clinical trials; COVID-19 vaccines; Dimers; Immune response; Infections; Medical research; Proteins; Severe acute respiratory syndrome coronavirus 2; Spike protein; Vaccines; Beijing China; China
• ISSN: 0140-6736; 1474-547X
• DOI: 10.1016/S0140-6736(23)01367-3

The surge of omicron subvariants BF.7 and BA.5.2 in China in December, 2022 caused nationwide breakthrough infections due to waning immunity and the increased resistance of the omicron subvariants to vaccine-induced immune responses.4 Omicron subvariants, including BQ.1, BQ.1.1, XBB, and XBB.1.5 continue to emerge worldwide, with further immune evasion due to their increased mutations in the spike protein (appendix p 6).5 Bivalent boosters containing omicron immunogen (BA.1 or BA.4–BA.5) have been widely used; however, the real-world effectiveness data are still emerging.6 We designed a heterotypic delta (B.1.617.2)–omicron (BA.1) chimeric RBD-dimer vaccine (ZF2202),7 which is being tested as a booster in clinical trials (NCT05616754 and NCT05574985). For participants who had received three doses of ZF2001 plus the heterodimer booster ZF2202, the neutralising GMTs against all pseudoviruses tested further increased by a factor of 1·1–2·1 versus group 4 (figure E; appendix pp 13, 16). The individual participant-level data that underlie the results reported in this Correspondence will be shared after de-identification.