Purpose

The influenza vaccine is essential in reducing the influenza burden, especially among healthcare workers (HCW). Experimental studies suggest both coronaviruses and influenza viruses engage with the angiotensin-converting enzyme 2 (ACE 2) and tetraspanin antibodies, and that ACE 2 tetraspanin antibodies in turn may inhibit both coronavirus and low-pathogenicity influenza A viruses (LP IAV) infections. This study aims to investigate the potential clinical association between receiving the 2019 influenza vaccine and the incidence of COVID-19 among HCW.

Methods

We designed a case–control study within a hospital setting in Iran when it became a center for treating COVID-19 patients. We collected data and calculated relevant incidence and associative measures among HCW who had received the 2019 influenza vaccine as compared to HCW who had not received the vaccine.

Results

Our total sample size was 261 HCW. Of 80 COVID-19 incident cases, three cases had received the influenza vaccine, while 87 of 181 controls had received the vaccine. The odds ratio (OR) and confidence interval (CI) of being vaccinated were 0.04 (95% CI: 0.01 to 0.14) among COVID-19 cases as compared to controls.

Conclusions

Significant findings suggest that the 2019 influenza vaccine may have a protective association against COVID-19 among HCW.

中文翻译：

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2019 年流感疫苗和医护人员中 COVID-19 发病率的病例对照研究

目的

流感疫苗对于减轻流感负担至关重要，尤其是在医护人员 (HCW) 中。实验研究表明，冠状病毒和流感病毒都与血管紧张素转换酶 2 (ACE 2) 和四跨膜抗体结合，而 ACE 2 四跨膜抗体又可能抑制冠状病毒和低致病性甲型流感病毒 (LP IAV) 感染。本研究旨在调查接受 2019 年流感疫苗与 HCW 中 COVID-19 发病率之间的潜在临床关联。

方法

当伊朗的一家医院成为治疗 COVID-19 患者的中心时，我们设计了一项病例对照研究。我们收集了数据并计算了接种 2019 年流感疫苗的 HCW 与未接种疫苗的 HCW 的相关发病率和相关指标。

结果

我们的总样本量为 261 名 HCW。在 80 例 COVID-19 事件病例中，3 例接受了流感疫苗，而 181 名对照中有 87 例接受了疫苗。与对照组相比，COVID-19 病例接种疫苗的优势比 (OR) 和置信区间 (CI) 为 0.04（95% CI：0.01 至 0.14）。

结论

重要发现表明，2019 年流感疫苗可能对医护人员中的 COVID-19 具有保护作用。