PDF(Pubmed)
Abstract：
OBJECTIVE: Asymptomatic SARS-CoV-2 infections were widely reported during the COVID-19 pandemic, acting as a hidden source of infection. Many existing studies investigating asymptomatic immunity failed to recruit true asymptomatic individuals. Thus, we conducted a longitudinal cohort study to evaluate humoral- and cell-mediated responses to infection and vaccination in well-defined asymptomatic young adults (the Asymptomatic COVID-19 in Education [ACE] cohort).
METHODS: Asymptomatic testing services located at three UK universities identified asymptomatic young adults who were subsequently recruited with age- and sex-matched symptomatic and uninfected controls. Blood and saliva samples were collected after SARS-CoV-2 Wuhan infection, and again after vaccination. 51 participant\'s anti-spike antibody titres, neutralizing antibodies, and spike-specific T-cell responses were measured, against both Wuhan and Omicron B.1.1.529.1.
RESULTS: Asymptomatic participants exhibited reduced Wuhan-specific neutralization antibodies pre- and post-vaccination, as well as fewer Omicron-specific neutralization antibodies post-vaccination, compared to symptomatic participants. Lower Wuhan and Omicron-specific IgG titres in asymptomatic individuals were also observed pre- and post-vaccination, compared to symptomatic participants. There were no differences in salivary IgA levels. Conventional flow cytometry analysis and multi-dimensional clustering analysis indicated unvaccinated asymptomatic participants had significantly fewer Wuhan-specific IL-2 secreting CD4+ CD45RA+ T cells and activated CD8+ T cells than symptomatic participants, though these differences dissipated after vaccination.
CONCLUSIONS: Asymptomatic infection results in decreased antibody and T cell responses to further exposure to SARS-CoV-2 variants, compared to symptomatic infection. Post-vaccination, antibody responses are still inferior, but T cell immunity increases to match symptomatic subjects, emphasising the importance of vaccination to help protect asymptomatic individuals against future variants.
METHODS: Asymptomatic testing services located at three UK universities identified asymptomatic young adults who were subsequently recruited with age- and sex-matched symptomatic and uninfected controls. Blood and saliva samples were collected after SARS-CoV-2 Wuhan infection, and again after vaccination. 51 participant\'s anti-spike antibody titres, neutralizing antibodies, and spike-specific T-cell responses were measured, against both Wuhan and Omicron B.1.1.529.1.
RESULTS: Asymptomatic participants exhibited reduced Wuhan-specific neutralization antibodies pre- and post-vaccination, as well as fewer Omicron-specific neutralization antibodies post-vaccination, compared to symptomatic participants. Lower Wuhan and Omicron-specific IgG titres in asymptomatic individuals were also observed pre- and post-vaccination, compared to symptomatic participants. There were no differences in salivary IgA levels. Conventional flow cytometry analysis and multi-dimensional clustering analysis indicated unvaccinated asymptomatic participants had significantly fewer Wuhan-specific IL-2 secreting CD4+ CD45RA+ T cells and activated CD8+ T cells than symptomatic participants, though these differences dissipated after vaccination.
CONCLUSIONS: Asymptomatic infection results in decreased antibody and T cell responses to further exposure to SARS-CoV-2 variants, compared to symptomatic infection. Post-vaccination, antibody responses are still inferior, but T cell immunity increases to match symptomatic subjects, emphasising the importance of vaccination to help protect asymptomatic individuals against future variants.
摘要：
目的：在COVID-19大流行期间广泛报道了无症状的SARS-CoV-2感染，充当隐藏的感染源。许多研究无症状免疫的现有研究未能招募真正的无症状个体。因此，我们进行了一项纵向队列研究,以评估明确定义的无症状年轻成年人对感染和疫苗接种的体液和细胞介导反应(教育中的无症状COVID-19[ACE]队列).
方法：位于英国三所大学的无症状测试服务机构确定了无症状的年轻人，他们随后被招募为年龄和性别匹配的有症状和未感染的对照。收集SARS-CoV-2武汉感染后的血液和唾液样本，在接种疫苗后。51名参与者的抗尖峰抗体滴度，中和抗体，并测量了尖峰特异性T细胞反应，针对武汉和OmicronB.1.1.529.1。
结果：无症状参与者在疫苗接种前后表现出武汉特异性中和抗体减少，以及更少的Omicron特异性中和抗体接种后，与有症状的参与者相比。在接种前和接种后也观察到无症状个体中武汉和Omicron特异性IgG滴度较低，与有症状的参与者相比。唾液IgA水平无差异。常规流式细胞术分析和多维聚类分析显示，未接种无症状参与者的武汉特异性IL-2分泌CD4+CD45RA+T细胞和活化CD8+T细胞明显少于有症状参与者。尽管这些差异在接种疫苗后消失了。
结论：无症状感染导致对进一步暴露于SARS-CoV-2变体的抗体和T细胞反应降低，与症状性感染相比。接种疫苗后，抗体反应仍然较差，但是T细胞免疫力增加以匹配有症状的受试者，强调接种疫苗的重要性，以帮助保护无症状的个体免受未来的变异。
方法：位于英国三所大学的无症状测试服务机构确定了无症状的年轻人，他们随后被招募为年龄和性别匹配的有症状和未感染的对照。收集SARS-CoV-2武汉感染后的血液和唾液样本，在接种疫苗后。51名参与者的抗尖峰抗体滴度，中和抗体，并测量了尖峰特异性T细胞反应，针对武汉和OmicronB.1.1.529.1。
结果：无症状参与者在疫苗接种前后表现出武汉特异性中和抗体减少，以及更少的Omicron特异性中和抗体接种后，与有症状的参与者相比。在接种前和接种后也观察到无症状个体中武汉和Omicron特异性IgG滴度较低，与有症状的参与者相比。唾液IgA水平无差异。常规流式细胞术分析和多维聚类分析显示，未接种无症状参与者的武汉特异性IL-2分泌CD4+CD45RA+T细胞和活化CD8+T细胞明显少于有症状参与者。尽管这些差异在接种疫苗后消失了。
结论：无症状感染导致对进一步暴露于SARS-CoV-2变体的抗体和T细胞反应降低，与症状性感染相比。接种疫苗后，抗体反应仍然较差，但是T细胞免疫力增加以匹配有症状的受试者，强调接种疫苗的重要性，以帮助保护无症状的个体免受未来的变异。
