Li Jiwei, Wu Jing, Long Qiuyue, Wu Yan'an, Hu Xiaoyi, He Yukun, Jiang Mingzheng, Li Jia, Zhao Lili, Yang Shuoqi, Chen Xiaoyong, Wang Minghui, Zheng Jianshi, Wu Fangfang, Wu Ruiliang, Ren Lihong, Bu Liang, Wang Houzhao, Li Ke, Fu Lijuan, Zhang Guojun, Zheng Yali, Gao Zhancheng
Department of Respiratory, Critical Care and Sleep Medicine, Xiang'an Hospital of Xiamen University, Xiamen, Fujian, China.
School of Medicine, Xiamen University, Xiamen, Fujian, China.
Research (Wash D C). 2022 Jun 16;2022:9873831. doi: 10.34133/2022/9873831. eCollection 2022.
The SARS-CoV-2 variants have been emerging and have made great challenges to current vaccine and pandemic control strategies. It is urgent to understand the current immune status of various Chinese populations given that the preexisting immunity has been established by national vaccination or exposure to past variants. Using sera from 85 individuals (including 21 convalescents of natural infection, 15 cases which suffered a breakthrough infection after being fully vaccinated, and 49 healthy vaccinees), we showed significantly enhanced neutralizing activities against SRAS-CoV-2 variants in convalescent sera, especially those who had been fully vaccinated. The neutralizing antibodies against Omicron were detectable in 75% of convalescents and 44.9% of healthy vaccinees ( = 0.006), with a GMT of 289.5, 180.9-463.3, and 42.6, 31.3-59, respectively. However, the neutralizing activities were weaker in young convalescents (aged < 18 y), with a detectable rate of 50% and a GMT of 46.4 against Omicron. We also examined and found no pan-sarbecovirus neutralizing activities in vaccinated SARS-CoV-1 survivors. A booster dose could further increase the breadth and magnitude of neutralization against WT and variants of concern (VOCs) to different degrees. In addition, we showed that COVID-19-inactivated vaccines can elicit Omicron-specific T-cell responses. The positive rates of ELISpot reactions were 26.7% (4/15) and 43.8% (7/16) in the full vaccination group and the booster vaccination group, respectively, although without statistically significant difference. The neutralizing antibody titers declined while T-cell responses remain consistent over 6 months. These findings will inform the optimization of public health vaccination and intervention strategies to protect diverse populations against SARS-CoV-2 variants. . Breakthrough infection significantly boosted neutralizing activities against SARS-CoV-2 variants as compared to booster immunization with inactivated vaccine. Vaccine-induced virus-specific T-cell immunity, on the other hand, may compensate for the shortfall. Furthermore, the public health system should target the most vulnerable group due to a poorer protective serological response in both infected and vaccinated adolescents.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）变体不断出现，给当前的疫苗和疫情防控策略带来了巨大挑战。鉴于通过国家疫苗接种或接触既往变体已建立起既往免疫力，了解中国不同人群当前的免疫状态迫在眉睫。我们使用了85名个体的血清（包括21名自然感染康复者、15名全程接种疫苗后出现突破性感染的病例以及49名健康接种者），结果显示康复者血清中针对SARS-CoV-2变体的中和活性显著增强，尤其是那些已全程接种疫苗的康复者。75%的康复者和44.9%的健康接种者可检测到针对奥密克戎的中和抗体（P = 0.006），其几何平均滴度（GMT）分别为289.5（95%可信区间[CI]：180.9 - 463.3）和42.6（95%CI：31.3 - 59）。然而，年轻康复者（年龄<18岁）的中和活性较弱，针对奥密克戎的可检测率为50%，GMT为46.4。我们还检测发现，接种过疫苗的SARS-CoV-1幸存者不存在泛沙贝病毒属中和活性。加强剂量可不同程度地进一步提高针对野生型（WT）和关注变体（VOCs）的中和广度和强度。此外，我们还表明，新冠病毒灭活疫苗可引发针对奥密克戎的特异性T细胞反应。全程接种组和加强接种组的酶联免疫斑点（ELISpot）反应阳性率分别为26.7%（4/15）和43.8%（7/16），尽管无统计学显著差异。中和抗体滴度在6个月内下降，而T细胞反应保持稳定。这些发现将为优化公共卫生疫苗接种和干预策略提供依据，以保护不同人群免受SARS-CoV-2变体感染。与灭活疫苗加强免疫相比，突破性感染显著增强了针对SARS-CoV-2变体的中和活性。另一方面，疫苗诱导的病毒特异性T细胞免疫可能弥补这一不足。此外，由于感染和接种疫苗的青少年血清学保护反应较差，公共卫生系统应针对最脆弱群体。
