School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
These authors contributed equally to the research.
Euro Surveill. 2022 May;27(18). doi: 10.2807/1560-7917.ES.2022.27.18.2200178.
BackgroundOmicron subvariant BA.2 circulation is rapidly increasing globally.AimWe evaluated the neutralising antibody response from vaccination or prior SARS-CoV-2 infection against symptomatic infection by BA.2 or other variants.MethodsUsing 50% plaque reduction neutralisation tests (PRNT), we assessed neutralising antibody titres to BA.2, wild type (WT) SARS-CoV-2 and other variants in Comirnaty or CoronaVac vaccinees, with or without prior WT-SARS-CoV-2 infection. Titres were also measured for non-vaccinees convalescing from a WT-SARS-CoV-2 infection. Neutralising antibodies in BA.2 and BA.1 breakthrough infections and in BA.2 infections affecting non-vaccinees were additionally studied.ResultsIn vaccinees or prior WT-SARS-CoV-2-infected people, BA.2 and BA.1 PRNT titres were comparable but significantly (p < 10 - 5) lower than WT. In each group of 20 vaccinees with (i) three-doses of Comirnaty, (ii) two CoronaVac followed by one Comirnaty dose, or (iii) one dose of either vaccine after a WT-SARS-CoV-2 infection, ≥ 19 individuals developed detectable (PRNT titre ≥ 10) antibodies to BA.2, while only 15 of 20 vaccinated with three doses of CoronaVac did. Comirnaty vaccination elicited higher titres to BA.2 than CoronaVac. In people convalescing from a WT-SARS-CoV-2 infection, a single vaccine dose induced higher BA.2 titres than three Comirnaty (p = 0.02) or CoronaVac (p = 0.00001) doses in infection-naïve individuals. BA.2 infections in previously uninfected and unvaccinated individuals elicited low (PRNT titre ≤ 80) responses with little cross-neutralisation of other variants. However, vaccinees with BA.1 or BA.2 breakthrough infections had broad cross-neutralising antibodies to WT viruses, and BA.1, BA.2, Beta and Delta variants.ConclusionsExisting vaccines can be of help against the BA.2 subvariant.
奥密克戎亚变体 BA.2 在全球范围内迅速传播。
我们评估了接种疫苗或先前感染 SARS-CoV-2 对 BA.2 或其他变体引起的有症状感染的中和抗体反应。
使用 50%噬斑减少中和试验 (PRNT)，我们评估了 Comirnaty 或 CoronaVac 疫苗接种者以及先前 WT-SARS-CoV-2 感染患者对 BA.2、野生型 (WT) SARS-CoV-2 和其他变体的中和抗体滴度。也测量了从 WT-SARS-CoV-2 感染中康复的非疫苗接种者的滴度。此外，还研究了 BA.2 和 BA.1 突破感染以及影响非疫苗接种者的 BA.2 感染中的中和抗体。
在疫苗接种者或先前 WT-SARS-CoV-2 感染者中，BA.2 和 BA.1 PRNT 滴度相当，但明显（p<10-5）低于 WT。在每组 20 名疫苗接种者中，（i）接种三剂 Comirnaty，（ii）接种两剂 CoronaVac 后接种一剂 Comirnaty，或（iii）在感染 WT-SARS-CoV-2 后接种一剂任一疫苗，有≥19 人产生了可检测到的（PRNT 滴度≥10）针对 BA.2 的抗体，而 20 名接种三剂 CoronaVac 的疫苗接种者中只有 15 人产生了抗体。Comirnaty 疫苗接种诱导的 BA.2 滴度高于 CoronaVac。在从 WT-SARS-CoV-2 感染中康复的人群中，与感染前未接种疫苗的个体相比，单次疫苗接种诱导的 BA.2 滴度高于三剂 Comirnaty（p=0.02）或 CoronaVac（p=0.00001）。先前未感染和未接种疫苗的个体中 BA.2 感染引起的反应较低（PRNT 滴度≤80），对其他变体的交叉中和作用很小。然而，BA.1 或 BA.2 突破感染的疫苗接种者对 WT 病毒以及 BA.1、BA.2、Beta 和 Delta 变体具有广泛的交叉中和抗体。
现有的疫苗可以对抗 BA.2 亚变体提供帮助。
