PDF(Pubmed)
Abstract：
The aim of this study was to evaluate the impact of index case vaccination on SARS-CoV-2 transmission to household contacts. In our epidemiological cohort study (May 2022-November 2023), we surveyed registered index case vaccination status and test results for contacts (testing on day 0, and on day 7 for negative contacts) and calculated the secondary attack rate (SAR), i.e., newly infected contacts/susceptible included contacts. The association of the independent variable, index case COVID-19 vaccination (yes/no), with household contact infection was determined using the adjusted odds ratio (aOR) and its 95% confidence interval (CI). We recorded 181 index cases and 314 contacts, of whom 250 agreed to participate; 16 contacts were excluded upon testing positive on day 0. Of the 234 included contacts, 49.1% were women, and the mean (SD) age was 51.9 (19.8) years. The overall SAR of 37.2% (87/234) was lower in the contacts of both vaccinated index cases (34.9% vs. 63.2%; p = 0.014) and index cases with a previous SARS-CoV-2 infection history (27.0% vs. 46.3%; p = 0.002). Index case vaccination showed a protective effect against infection for their household contacts (aOR = 0.21; 95% CI: 0.07, 0.67). The household SAR was high when the Omicron variant circulated. Vaccinated index cases were less likely to transmit SARS-CoV-2 to their contacts.
摘要：
这项研究的目的是评估索引病例疫苗接种对SARS-CoV-2传播给家庭接触者的影响。在我们的流行病学队列研究（2022年5月至2023年11月）中，我们调查了接触者的注册索引病例疫苗接种状况和测试结果（第0天和第7天的阴性接触者的测试），并计算了二次发作率（SAR），即，新感染的接触者/易感者包括接触者。自变量的关联，指示病例COVID-19疫苗接种（是/否），使用校正比值比(aOR)及其95%置信区间(CI)确定家庭接触感染.我们记录了181个索引案例和314个联系人，其中250人同意参加；第0天检测呈阳性的16名联系人被排除在外。在包括的234个联系人中，49.1%是女性，平均（SD）年龄为51.9（19.8）岁。在两个接种指数病例的接触中，37.2%(87/234)的总体SAR较低(34.9%vs.63.2%；p=0.014）和既往有SARS-CoV-2感染史的指数病例（27.0%vs.46.3%；p=0.002）。索引病例疫苗接种对其家庭接触者具有预防感染的保护作用（aOR=0.21；95％CI：0.07，0.67）。Omicron变体流通时，家庭SAR很高。接种过的指数病例不太可能将SARS-CoV-2传播给他们的接触者。
