Israel is currently experiencing a new wave of CoVid-19 infection, six months after implementing a national vaccination campaign. We carried out three discrete analyses using data from a large Israeli HMO to determine whether IgG levels of those fully vaccinated drop over time, the relationship between IgG titer and subsequent PCR-confirmed infection, and compare PCR-confirmed infection rates by period of vaccination. We found that mean IgG antibody levels steadily decreased over the six-month period in the total tested population, and in all age groups. An inverse relationship was found between IgG titer and subsequent CoVid-19 infection (PCR-positive). Those participants vaccinated in the first two months of the campaign were more likely to become infected than those subsequently vaccinated. The 60+ vaccinated had lower initial IgG levels, and were at greater risk of infection. The findings support the decision to add a booster vaccine for those aged 60 and over.

中文翻译：

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接种 6 个月后 mRNA BNT162b2 疫苗的有效性：来自以色列大型 HMO 的发现

在实施全国疫苗接种运动六个月后，以色列目前正在经历新一波 CoVid-19 感染。我们使用来自大型以色列 HMO 的数据进行了三项离散分析，以确定那些完全接种疫苗的人的 IgG 水平是否随时间下降、IgG 滴度与随后的 PCR 确认感染之间的关系，并比较不同接种时期的 PCR 确认感染率。我们发现，在整个测试人群和所有年龄组中，平均 IgG 抗体水平在 6 个月内稳步下降。在 IgG 滴度和随后的 CoVid-19 感染（PCR 阳性）之间发现了反比关系。在运动的前两个月接种疫苗的参与者比随后接种疫苗的参与者更有可能被感染。接种疫苗的 60+ 人的初始 IgG 水平较低，并且感染的风险更大。调查结果支持为 60 岁及以上的人添加加强疫苗的决定。