Abstract：
OBJECTIVE: To assess the dynamics of the anti-SARS-CoV-2 IgG antibody levels and their efficacy against COVID-19.
METHODS: We conducted a longitudinal serological analysis of 852 breakthrough COVID-19 infections among the community-based population in Yichang, China. Anti-SARS-CoV-2 IgG levels were measured by chemiluminescence at approximately 3, 4, and 9 months after infection. A linear mixed model predicted IgG antibody decline over 18 months. The effectiveness of antibodies in preventing symptomatic and severe infections was determined using an existing meta-regression model.
RESULTS: IgG antibodies slowly declined after breakthrough infections. Initially high at around 3 months (339.44 AU/mL, IQR: 262.78-382.95 AU/mL), levels remained significant at 9 months (297.74 AU/mL, IQR: 213.22-360.62 AU/mL). The elderly (≥60 years) had lower antibody levels compared to the young (<20 years) (P < 0.001). The protective efficacy of antibodies against symptomatic and severe infections was lower in the elderly (≥60 years) (78.34% and 86.33%) compared to the young (<20 years) (96.56% and 98.75%) after 1 year.
CONCLUSIONS: The study indicated a slow decline in anti-SARS-CoV-2 IgG antibodies, maintaining considerable efficacy for over 1 year. However, lower levels in the elderly suggest reduced protective effects, underscoring the need for age-specific vaccination strategies.
METHODS: We conducted a longitudinal serological analysis of 852 breakthrough COVID-19 infections among the community-based population in Yichang, China. Anti-SARS-CoV-2 IgG levels were measured by chemiluminescence at approximately 3, 4, and 9 months after infection. A linear mixed model predicted IgG antibody decline over 18 months. The effectiveness of antibodies in preventing symptomatic and severe infections was determined using an existing meta-regression model.
RESULTS: IgG antibodies slowly declined after breakthrough infections. Initially high at around 3 months (339.44 AU/mL, IQR: 262.78-382.95 AU/mL), levels remained significant at 9 months (297.74 AU/mL, IQR: 213.22-360.62 AU/mL). The elderly (≥60 years) had lower antibody levels compared to the young (<20 years) (P < 0.001). The protective efficacy of antibodies against symptomatic and severe infections was lower in the elderly (≥60 years) (78.34% and 86.33%) compared to the young (<20 years) (96.56% and 98.75%) after 1 year.
CONCLUSIONS: The study indicated a slow decline in anti-SARS-CoV-2 IgG antibodies, maintaining considerable efficacy for over 1 year. However, lower levels in the elderly suggest reduced protective effects, underscoring the need for age-specific vaccination strategies.
摘要：
目的：评估抗SARS-CoV-2IgG抗体水平的动态变化及其对COVID-19的疗效。
方法：我们对宜昌市社区人群中852例突破性COVID-19感染进行了纵向血清学分析，中国。在感染后约3、4和9个月通过化学发光测量抗SARS-CoV-2IgG水平。线性混合模型预测IgG抗体在18个月内下降。使用现有的meta回归模型确定抗体在预防有症状和严重感染中的有效性。
结果：IgG抗体在突破性感染后缓慢下降。最初在3个月左右高（339.44AU/mL，IQR:262.78-382.95AU/mL),水平在9个月时仍然显著(297.74AU/mL，IQR：213.22-360.62AU/mL）。老年人（≥60岁）的抗体水平低于年轻人（<20岁）（P<0.001）。一年后，老年人（≥60岁）（78.34％和86.33％）对有症状和严重感染的抗体的保护效力低于年轻人（<20岁）（96.56％和98.75％）。
结论：该研究表明抗SARS-CoV-2IgG抗体缓慢下降，保持相当的疗效一年以上。然而,老年人的低水平表明保护作用降低，强调需要针对特定年龄的疫苗接种策略。
方法：我们对宜昌市社区人群中852例突破性COVID-19感染进行了纵向血清学分析，中国。在感染后约3、4和9个月通过化学发光测量抗SARS-CoV-2IgG水平。线性混合模型预测IgG抗体在18个月内下降。使用现有的meta回归模型确定抗体在预防有症状和严重感染中的有效性。
结果：IgG抗体在突破性感染后缓慢下降。最初在3个月左右高（339.44AU/mL，IQR:262.78-382.95AU/mL),水平在9个月时仍然显著(297.74AU/mL，IQR：213.22-360.62AU/mL）。老年人（≥60岁）的抗体水平低于年轻人（<20岁）（P<0.001）。一年后，老年人（≥60岁）（78.34％和86.33％）对有症状和严重感染的抗体的保护效力低于年轻人（<20岁）（96.56％和98.75％）。
结论：该研究表明抗SARS-CoV-2IgG抗体缓慢下降，保持相当的疗效一年以上。然而,老年人的低水平表明保护作用降低，强调需要针对特定年龄的疫苗接种策略。
