Department of Acute Infectious Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.
National Health Commission (NHC) Key Laboratory of Enteric Pathogenic Microbiology, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.
Front Public Health. 2024 May 30;12:1364048. doi: 10.3389/fpubh.2024.1364048. eCollection 2024.
It is important to figure out the immunity of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) reinfection to understand the response of humans to viruses. A serological survey for previously infected populations in Jiangsu Province was conducted to compare the antibody level of SARS-CoV-2 in reinfection by Omicron or not.
Reinfection with SARS-CoV-2 was defined as an individual being infected again after 90 days of the initial infection. Telephone surveys and face-to-face interviews were implemented to collect information. Experimental and control serum samples were collected from age-sex-matched reinfected and non-reinfected cases, respectively. IgG anti-S and neutralizing antibodies (Nab) concentrations were detected by the Magnetism Particulate Immunochemistry Luminescence Method (MCLIA). Antibody titers were log(2)-transformed and analyzed by a two-tailed Mann-Whitney test. Subgroup analysis was conducted to explore the relationship between the strain type of primary infection, SARS-Cov-2 vaccination status, and antibody levels. Multivariate linear regression models were used to identify associations between reinfection with IgG and Nab levels.
Six hundred thirty-one individuals were enrolled in this study, including 327 reinfected cases and 304 non-reinfected cases. The reinfection group had higher IgG (5.65 AU/mL vs. 5.22 AU/mL) and Nab (8.02 AU/mL vs. 7.25 AU/mL) levels compared to the non-reinfection group ( < 0.001). Particularly, individuals who had received SARS-CoV-2 vaccination or were initially infected with the Wild type and Delta variant showed a significant increase in antibody levels after reinfection. After adjusting demographic variables, vaccination status and the type of primary infection together, IgG and Nab levels in the reinfected group increased by log(2)-transformed 0.71 and 0.64 units, respectively ( < 0.001). This revealed that reinfection is an important factor that affects IgG and Nab levels in the population.
Reinfection with Omicron in individuals previously infected with SARS-CoV-2 enhances IgG and Nab immune responses.
了解严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）再感染的免疫情况对于了解人类对病毒的反应非常重要。本研究对江苏省既往感染人群进行了血清学调查，以比较奥密克戎再感染与非再感染人群的 SARS-CoV-2 抗体水平。
SARS-CoV-2 再感染定义为初次感染后 90 天内再次感染。通过电话调查和面对面访谈收集信息。分别采集年龄、性别匹配的再感染和非再感染病例的实验和对照血清样本。采用磁微粒化学发光法（MCLIA）检测 IgG 抗-S 和中和抗体（Nab）浓度。采用双尾曼-惠特尼 U 检验对抗体滴度进行对数（2）转换分析。进行亚组分析以探讨初次感染株型、SARS-CoV-2 疫苗接种状态与抗体水平的关系。采用多元线性回归模型确定再感染与 IgG 和 Nab 水平的关系。
本研究共纳入 631 名个体，其中 327 例再感染，304 例非再感染。与非再感染组相比，再感染组 IgG（5.65 AU/mL 比 5.22 AU/mL）和 Nab（8.02 AU/mL 比 7.25 AU/mL）水平更高（ < 0.001）。特别是，接种 SARS-CoV-2 疫苗或初次感染野生型和德尔塔变异株的个体，再感染后抗体水平显著升高。在校正人口统计学变量、疫苗接种状态和初次感染类型后，再感染组 IgG 和 Nab 水平分别增加了对数（2）转换 0.71 和 0.64 单位（ < 0.001）。这表明再感染是影响人群 IgG 和 Nab 水平的重要因素。
既往感染 SARS-CoV-2 的个体再感染奥密克戎可增强 IgG 和 Nab 免疫应答。
