Background

Despite high vaccine coverage and effectiveness, the incidence of symptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been increasing in Israel. Whether the increasing incidence of infection is due to waning immunity after the receipt of two doses of the BNT162b2 vaccine is unclear.

Methods

We conducted a 6-month longitudinal prospective study involving vaccinated health care workers who were tested monthly for the presence of anti-spike IgG and neutralizing antibodies. Linear mixed models were used to assess the dynamics of antibody levels and to determine predictors of antibody levels at 6 months.

Results

The study included 4868 participants, with 3808 being included in the linear mixed-model analyses. The level of IgG antibodies decreased at a consistent rate, whereas the neutralizing antibody level decreased rapidly for the first 3 months with a relatively slow decrease thereafter. Although IgG antibody levels were highly correlated with neutralizing antibody titers (Spearman’s rank correlation between 0.68 and 0.75), the regression relationship between the IgG and neutralizing antibody levels depended on the time since receipt of the second vaccine dose. Six months after receipt of the second dose, neutralizing antibody titers were substantially lower among men than among women (ratio of means, 0.64; 95% confidence interval [CI], 0.55 to 0.75), lower among persons 65 years of age or older than among those 18 to less than 45 years of age (ratio of means, 0.58; 95% CI, 0.48 to 0.70), and lower among participants with immunosuppression than among those without immunosuppression (ratio of means, 0.30; 95% CI, 0.20 to 0.46).

Conclusions

Six months after receipt of the second dose of the BNT162b2 vaccine, humoral response was substantially decreased, especially among men, among persons 65 years of age or older, and among persons with immunosuppression.

中文翻译：

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6 个月内对 BNT162b2 Covid-19 疫苗的免疫体液反应减弱

背景

尽管疫苗覆盖率和有效性很高，但以色列严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 症状感染的发生率一直在增加。目前尚不清楚感染发生率的增加是否是由于接受两剂 BNT162b2 疫苗后免疫力下降所致。

方法

我们进行了一项为期 6 个月的纵向前瞻性研究，涉及接种疫苗的医护人员，他们每月接受一次抗尖峰 IgG 和中和抗体的检测。使用线性混合模型来评估抗体水平的动态并确定 6 个月时抗体水平的预测因子。

结果

该研究包括 4868 名参与者，其中 3808 名参与者被纳入线性混合模型分析。IgG抗体水平以一致的速度下降，而中和抗体水平在前3个月迅速下降，此后下降相对缓慢。尽管 IgG 抗体水平与中和抗体滴度高度相关（Spearman 等级相关性在 0.68 和 0.75 之间），但 IgG 和中和抗体水平之间的回归关系取决于自接受第二剂疫苗以来的时间。接受第二剂疫苗六个月后，男性中和抗体滴度显着低于女性（平均值比为 0.64；95% 置信区间 [CI]，0.55 至 0.75），65 岁或以上人群中的中和抗体滴度低于女性。 18 岁至 45 岁以下人群中（平均值比率为 0.58；95% CI，0.48 至 0.70），并且接受免疫抑制的参与者低于未接受免疫抑制的参与者（平均值比率为 0.30；95% CI，0.20 至 0.70）。 0.46）。

结论

接受第二剂 BNT162b2 疫苗六个月后，体液反应大幅下降，尤其是男性、65 岁或以上的人群以及免疫抑制患者。