Sá Silva Susana, Severo Milton, Norton Pedro, Moreira André
Basic and Clinical Immunology Unit, Department of Pathology, Faculty of Medicine, University of Porto, Porto, Portugal.
São João University Hospital Center, Porto, Portugal.
Porto Biomed J. 2023 Aug 3;8(4):e223. doi: 10.1097/j.pbj.0000000000000223. eCollection 2023 Jul-Aug.
Vaccination for influenza has been essential over the years to protect the most vulnerable populations. Moreover, it was recently suggested that influenza vaccination might confer some nonspecific immunity to other viruses and be associated with a lower risk for coronavirus disease 2019 (COVID-19) morbidity and mortality. Therefore, we aimed to assess the effectiveness of repetitive influenza vaccination against SARS-CoV-2 infection in a cohort of health care workers (HCWs). This study was conducted among HCWs at São João University Hospital Center (CHUSJ), Porto, Portugal, a tertiary reference hospital for diagnosis and therapy, one of the largest hospitals in the country with approximately 6000 HCWs. We analyzed databases for influenza vaccination conducted between 2012 and 2019 and COVID-19 laboratory testing retrieved from the first and last registered positive COVID test date before HCW's COVID-19 vaccination started. The study outcome was the incidence of the first SARS-CoV-2 infection, as determined by reverse transcription polymerase chain reaction (RT-PCR). Age and sex were considered potential confounders. We used multivariable Cox regression to estimate odds ratios. Neither the absolute number nor the proportion of influenza shots influenced the risk of getting infected by SARS-CoV-2 (adjusted odds ratio 1.02, 95% CI: 0.9-1.06 and 1.17 95% CI: 0.86-1.58, respectively). Similar findings were observed in most cases when the analysis was restricted by year. The findings from our retrospective observational analysis of a HCWs cohort failed to support any protective effect between repetitive influenza vaccination and SARS-CoV-2 infection.
多年来，流感疫苗接种对于保护最脆弱人群至关重要。此外，最近有研究表明，流感疫苗接种可能会赋予针对其他病毒的一些非特异性免疫力，并与降低2019冠状病毒病（COVID-19）的发病率和死亡率相关。因此，我们旨在评估在一组医护人员（HCW）中重复接种流感疫苗对严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）感染的有效性。本研究在葡萄牙波尔图圣若昂大学医院中心（CHUSJ）的医护人员中进行，该中心是一家诊断和治疗的三级转诊医院，也是该国最大的医院之一，约有6000名医护人员。我们分析了2012年至2019年期间进行流感疫苗接种的数据库，以及从医护人员COVID-19疫苗接种开始前首次和最后一次登记的COVID检测阳性日期检索到的COVID-19实验室检测数据。研究结果是首次SARS-CoV-2感染的发生率，通过逆转录聚合酶链反应（RT-PCR）确定。年龄和性别被视为潜在的混杂因素。我们使用多变量Cox回归来估计比值比。流感疫苗接种的绝对数量和比例均未影响感染SARS-CoV-2的风险（调整后的比值比分别为1.02，95%置信区间：0.9 - 1.06和1.17，95%置信区间：0.86 - 1.58）。在按年份进行分析时，大多数情况下观察到了类似的结果。我们对一组医护人员进行的回顾性观察分析结果未能支持重复接种流感疫苗与SARS-CoV-2感染之间存在任何保护作用。
