Core_plus Option_B_C_Influenza Vaccine Effectiveness in a Wisconsin Population

描述（由申请方提供）：流感是发病和死亡的重要原因，流感疫苗接种是流感预防的关键组成部分。 与许多其他感染不同，流感病毒在不断演变，疫苗成分也会根据这些变化进行修改。 因此，流感疫苗的有效性每年都有所不同，并且可能因亚型、抗原匹配和年龄组而异。 需要对疫苗临床有效性进行年度评估，以评估国家疫苗建议和政策的影响，了解病毒抗原性变化与临床保护之间的关系，并为大流行期间的疫苗评估做好准备。对疫苗有效性的中期估计对公共卫生机构和医生是有用的。 为了估计疫苗有效性，将在流感季节从预定义的人群队列中招募急性呼吸道疾病（发热、发热或咳嗽）患者。 入组将在门诊、紧急护理或急诊科就诊期间或之后进行。大多数登记将发生在护理点，但一些患者将通过电话联系，并在接受急性呼吸道疾病诊断后的第二天进行资格筛选。在获得知情同意后，将使用核酸扩增试验（RT-PCR）检测鼻和咽拭子中的甲型和B型流感病毒。 将对阳性样本进行病毒培养，并将一个子集送至CDC进行抗原表征。 流感疫苗接种状态将由经验证的免疫登记处确定。 将使用病例对照方法计算疫苗有效性，其中病例包括RT-PCR证实的流感受试者，对照包括非流感呼吸道疾病（RT-PCR阴性）的研究受试者。 将通过获得住院和X线证实的肺炎发作数据来评估严重程度。 将向CDC提供数据，以便与其他参与研究中心进行综合分析，包括用于有效性中期分析的中期数据。 将针对不同年龄组、每种流感类型/亚型和高风险个体计算疫苗有效性的单独估计值。 我们将估计接种疫苗和未接种疫苗的人群中接受医疗护理的流感的发病率。 拟议的研究将1）生成数据，以支持和告知医生实践和公共卫生机构的流感预防建议，2）增加我们对抗原距离及其与临床疫苗有效性的关系的理解，3）提供一个平台来测量VE并研究流感大流行期间的流行病学。

DESCRIPTION (provided by applicant): Influenza is an important cause of morbidity and mortality, and influenza vaccination is a key component of influenza prevention. Unlike many other infections, influenza viruses are constantly evolving and the vaccine components are modified to account for these changes. As a result, the effectiveness of influenza vaccine varies from year to year, and it can vary by subtype, antigenic match, and age group. Annual assessment of clinical vaccine effectiveness is needed to evaluate the impact of national vaccine recommendations and policies, understand the relationship between antigenic changes in viruses and clinical protection, and prepare for vaccine assessment during a pandemic. Interim, mid-season estimates of vaccine effectiveness are useful for public health agencies and physicians. To estimate vaccine effectiveness, patients with acute respiratory illness (fever, feverishness or cough) will be enrolled from a predefined population cohort during the influenza season. Enrollment will occur during or after an outpatient, urgent care or emergency department encounter. Most enrollments will occur at the point of care, but some patients will be contacted by phone and screened for eligibility on the day after receiving a diagnosis for acute respiratory illness. After obtaining informed consent, nose and throat swabs will be tested for influenza A and B using a nucleic acid amplification test (RT-PCR). Viral cultures will be performed on positives, and a subset will be sent to CDC for antigenic characterization. Influenza immunization status will be determined by a validated immunization registry. Vaccine effectiveness will be calculated using a case control approach where cases include participants with RT-PCR confirmed influenza and controls include study participants with non-influenza respiratory illness (negative RT-PCR). Severity will be assessed by obtaining data on hospital admissions and x-ray confirmed pneumonia episodes. Data will provided to CDC for combined analyses with other participating sites, including mid-season data for interim analysis of effectiveness. Separate estimates of vaccine effectiveness will be calculated for different age groups, for each influenza type/subtype, and for high risk individuals. We will estimate the population-based attack rate for medically attended influenza in vaccinated and unvaccinated individuals. The proposed research will 1) generate data to support and inform physician practice and public health agency recommendations for influenza prevention, 2) increase our understanding of antigenic distance and its relationship to clinical vaccine effectiveness, and 3) provide a platform to measure VE and study the epidemiology of influenza during a pandemic.