Yin Zhiying, Yin Mengcheng, Zhao Fei, Fu Canya, Xu Wenjie, Fang Quanjun, Gong Xiaoying, Cao Guoping, Zheng Canjie
Department of Immunity, Quzhou Center for Disease Control and Prevention, Quzhou, Zhejiang, China.
Second Clinical Medical College, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Front Immunol. 2025 Jul 28;16:1576016. doi: 10.3389/fimmu.2025.1576016. eCollection 2025.
To investigate the factors influencing SARS-CoV-2 IgG antibody levels and protection in a population that has experienced both vaccination and COVID-19 infections, predominantly caused by the Omicron BA.5.2 and BF.7 variants.
Anti-SARS-CoV-2 IgG antibody levels were measured using chemiluminescent microparticle immunoassay (CMIA). Multivariate regression analyses assessed factors influencing antibody levels, and decision tree models predicted variable priorities.
Among the 3494 participants, the median (IQR) anti-SARS-CoV-2 IgG level was 396.53 (280.51-471.03) AU/mL, with a seropositive rate of 97.28%. Multivariate analysis revealed that vaccination status, infection status, residence county, occupation, and vaccination interval were significantly associated with antibody concentration. The decision tree model indicated that vaccination had a greater effect on antibody concentration than infection, while infection had a stronger impact on seropositivity. The Breakthrough Infection group had the highest antibody concentration compared with other groups.
Vaccination and infection were identified as the primary determinants of SARS-CoV-2 IgG antibody levels, with hybrid immunity significantly enhancing antibody responses. New evaluation methods or revised detection thresholds were needed to better assess population immunity.
在一个既接种过疫苗又感染过新冠病毒（主要由奥密克戎BA.5.2和BF.7变异株引起）的人群中，调查影响新冠病毒SARS-CoV-2 IgG抗体水平及保护作用的因素。
采用化学发光微粒子免疫分析（CMIA）测定抗SARS-CoV-2 IgG抗体水平。多因素回归分析评估影响抗体水平的因素，决策树模型预测变量优先级。
在3494名参与者中，抗SARS-CoV-2 IgG水平的中位数（四分位间距）为396.53（280.51 - 471.03）AU/mL，血清阳性率为97.28%。多因素分析显示，疫苗接种状况、感染状况、居住县、职业和疫苗接种间隔与抗体浓度显著相关。决策树模型表明，疫苗接种对抗体浓度的影响大于感染，而感染对血清阳性率的影响更强。与其他组相比，突破性感染组的抗体浓度最高。
疫苗接种和感染被确定为SARS-CoV-2 IgG抗体水平的主要决定因素，混合免疫显著增强抗体反应。需要新的评估方法或修订检测阈值以更好地评估人群免疫力。
