BACKGROUND COVID-19 is a strong risk factor for venous thromboembolism (VTE). Few studies have evaluated the effectiveness of COVID-19 vaccination in preventing hospitalization for COVID-19 with VTE. METHODS Adults hospitalized at 21 sites between March 2021 and October 2022 with symptoms of acute respiratory illness were assessed for COVID-19, completion of the original monovalent mRNA COVID-19 vaccination series, and VTE. Prevalence of VTE was compared between unvaccinated and vaccinated patients with COVID-19. Vaccine effectiveness in preventing COVID-19 hospitalization with VTE was calculated using a test negative design. Vaccine effectiveness was also stratified by predominant circulating SARS-CoV-2 variant. RESULTS Among 18,811 patients (median age 63 [IQR:50-73], 49% women, 59% non-Hispanic White, 20% non-Hispanic Black, 14% Hispanic, and median of 2 comorbid conditions [IQR:1-3]), 9,792 were admitted with COVID-19 (44% vaccinated) and 9,019 were test-negative controls (73% vaccinated). Among patients with COVID-19, 601 were diagnosed with VTE by hospital day 28, of whom 170 were vaccinated. VTE was more common among unvaccinated than vaccinated COVID-19 patients (7.8% versus 4.0%; p=0.001). Vaccine effectiveness against COVID-19 hospitalization with VTE was 84% (95% CI: 80-87%) overall. Vaccine effectiveness stratified by predominant circulating variant was 88% (73-95%) for alpha, 93% (90-95%) for delta, and 68% (58-76%) for omicron variants. CONCLUSIONS AND RELEVANCE Vaccination with the original monovalent mRNA series was associated with a decrease in COVID-19 hospitalization with VTE, though data detailing prior history of VTE and use of anticoagulation were not available. These findings will inform risk-benefit considerations for those considering vaccination.

中文翻译：

---

原始单价 mRNA COVID-19 疫苗接种系列对 COVID-19 相关静脉血栓栓塞住院的有效性。


背景 COVID-19 是静脉血栓栓塞 （VTE） 的强危险因素。很少有研究评估 COVID-19 疫苗接种在预防 COVID-19 因 VTE 住院方面的有效性。方法 对 2021 年 3 月至 2022 年 10 月期间在 21 个地点住院的有急性呼吸系统疾病症状的成人进行了 COVID-19 评估，完成了原始单价 mRNA COVID-19 疫苗接种系列和 VTE。比较了未接种疫苗和接种疫苗的 COVID-19 患者之间的 VTE 患病率。使用检测阴性设计计算疫苗预防 COVID-19 因 VTE 住院的有效性。疫苗有效性也按主要流行的 SARS-CoV-2 变体进行分层。结果在 18,811 名患者中（中位年龄 63 [IQR：50-73]，49% 女性，59% 非西班牙裔白人，20% 非西班牙裔黑人，14% 西班牙裔，以及 2 种合并症的中位数 [IQR：1-3]），9,792 名因 COVID-19 入院（44% 接种疫苗），9,019 名为检测阴性对照（73% 接种疫苗）。在 COVID-19 患者中，601 人在住院第 28 天被诊断出患有 VTE，其中 170 人接种了疫苗。VTE 在未接种疫苗的 COVID-19 患者中比在接种疫苗的 COVID-19 患者中更常见 （7.8% 对 4.0%;p=0.001）。总体而言，疫苗对 COVID-19 因 VTE 住院的有效性为 84% （95% CI： 80-87%）。按主要流行变体分层的疫苗有效性为 alpha 为 88% （73-95%），delta 为 93% （90-95%） 和 omicron 变体为 68% （58-76%）。结论和相关性 使用原始单价 mRNA 系列接种疫苗与 COVID-19 因 VTE 住院率的降低有关，尽管没有详细说明 VTE 既往病史和抗凝治疗使用的数据。 这些发现将为考虑接种疫苗的人提供风险收益考虑。