School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, China; Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
J Clin Virol. 2022 Nov;156:105273. doi: 10.1016/j.jcv.2022.105273. Epub 2022 Aug 31.
BA.2.12.1, BA.4 and BA.5 subvariants of SARS-CoV-2 variant-of-concern (VOC) Omicron (B.1.1.529) are spreading globally. They demonstrate higher transmissibility and immune escape.
Determine BA.2.12.1, BA.4 and BA.5 virus plaque reduction neutralization test (PRNT) antibody titres in individuals recently vaccinated with BNT162b2 (n = 20) or CoronaVac (n = 20) vaccines or those convalescent from ancestral wild- type (WT) SARS-CoV-2 (n = 20) or BA.2 infections with (n = 17) or without (n = 7) prior vaccination.
Relative to neutralization of the WT virus, those vaccinated with BNT162b2 had 4.8, 3.4, 4.6, 11.3 and 15.5-fold reductions of geometric mean antibody titres (GMT) to BA.1, BA.2, BA.2.12.1, BA.4 and BA.5 viruses, respectively. Similarly, those vaccinated with CoronaVac had 8.0, 7.0, 11.8, 12.0 and 12.0 fold GMT reductions and those with two doses of CoronaVac boosted by BNT162b2 had 6.1, 6.7, 6,3, 13.0 and 21.2 fold GMT reductions to these viruses, respectively. Vaccinated individuals with BA.2 breakthrough infections had higher GMT antibody levels vs. BA.4 (36.9) and BA.5 (36.9) than unvaccinated individuals with BA.2 infections (BA.4 GMT 8.2; BA.5 GMT 11.0).
BA.4 and BA.5 subvariants were less susceptible to BNT162b2 or CoronaVac vaccine elicited antibody neutralization than subvariants BA.1, BA.2 and BA.2.12.1. Nevertheless, three doses BNT162b2 or booster of BNT162b2 following two doses of CoronaVac elicited detectable BA.4 and BA.5 neutralizing antibody responses while those vaccinated with three doses of CoronaVac largely fail to do so. BA.2 infections in vaccinated individuals led to higher levels of BA.4 or BA.5 neutralizing antibody compared to those who were vaccine-naive.
SARS-CoV-2 变体关注变种（VOC）奥密克戎（B.1.1.529）的 BA.2.12.1、BA.4 和 BA.5 亚变体正在全球范围内传播。它们表现出更高的传染性和免疫逃逸能力。
确定最近接种 BNT162b2（n=20）或科兴（n=20）疫苗或从原始野生型（WT）SARS-CoV-2（n=20）或 BA.2 感染中康复的个体（n=17）的 BA.2.12.1、BA.4 和 BA.5 病毒蚀斑减少中和试验（PRNT）抗体滴度，其中接种者有（n=17）或没有（n=7）先前接种疫苗。
与 WT 病毒的中和作用相比，接种 BNT162b2 的个体对 BA.1、BA.2、BA.2.12.1、BA.4 和 BA.5 病毒的几何平均抗体滴度（GMT）分别降低了 4.8、3.4、4.6、11.3 和 15.5 倍。同样，接种科兴的个体GMT 降低了 8.0、7.0、11.8、12.0 和 12.0 倍，而接种两剂科兴并加强接种 BNT162b2 的个体对这些病毒的 GMT 降低了 6.1、6.7、6、3、13.0 和 21.2 倍。与未接种 BA.2 感染的个体相比，BA.2 突破性感染的接种个体对 BA.4（36.9）和 BA.5（36.9）的 GMT 抗体水平更高。
与 BA.1、BA.2 和 BA.2.12.1 亚变体相比，BA.4 和 BA.5 亚变体对 BNT162b2 或科兴疫苗诱导的抗体中和的敏感性较低。然而，三剂 BNT162b2 或两剂科兴加强接种 BNT162b2 可引起可检测的 BA.4 和 BA.5 中和抗体反应，而接种三剂科兴的个体则基本不能引起。与疫苗未接种的个体相比，接种个体的 BA.2 感染导致更高水平的 BA.4 或 BA.5 中和抗体。
