Annual Estimates of Influenza Vaccine Effectiveness: Davidson County, TN

描述(由调查人员提供)：流感病毒每年感染5%至20%的美国人口，每年平均导致226,000人住院和34,000人死亡。一年一度的流感疫苗接种建议传统上是针对65岁以上的人；其他有健康状况的人也是流感相关并发症的高危人群；以及那些被认为是高危人群的密切接触者。这些建议最近已扩大到包括50岁至的成年人和6个月至5岁的儿童。这些公共政策建议现在包括了大多数美国人，需要仔细评估，以确保它们产生预期的效果。由于流感病毒和疫苗每年都在变化，因此需要对疫苗效力进行年度评估。在过去的八年里，作为疾控中心新疫苗监测网络的一部分，我们参与了戴维森县纳什维尔(人口578,698)对患有急性呼吸道疾病的幼儿的流感的基于人群的监测。在NIH疫苗治疗和评估部的两年支持下，我们在2006-2007年流感季节启动了对50岁成年人的类似监测，该监测将持续到2007-2008年。我们的经验独特地使我们有资格有效地启动执行疫苗有效性年度评估所需的监测活动。我们已经与戴维森县医院建立了合作关系，这些医院为95%的县儿童和50%的因急性呼吸道疾病住院的县成年人提供护理。已经建立了登记和检测合格患者的程序，制定了数据收集表格并进行了实地测试，并改进和验证了实验室程序。我们建议对成人和儿童的实验室确诊流感进行积极的人群监测，以确定该县与流感相关的住院和急诊科就诊率。我们将与疾控中心和其他合作协议参与者合作，每年两次评估流感疫苗的有效性，一次在流感季节中期，一次在流感季节结束时。我们建议采用配对病例对照分析来评估疫苗的有效性。研究对象将是因急性呼吸道疾病住院或急诊室就诊的6个月或以上的县儿童和成年人的系统样本。登记的受试者将为研究实验室的流感测试提供鼻拭子和咽喉拭子。受试者或其父母/监护人将提供有关其急性疾病、病史和流感疫苗接种情况的信息。病例将通过逆转录-聚合酶链式反应(RT-PCR)或病毒培养检测流感病毒来确定。所有RT-PCR和培养均为阴性的研究对象将有资格成为对照。在第一年，我们还将收集、处理、存储和运送给疾控中心，450对血清和150对外周血单核细胞样本，以评估50岁成年人对流感疫苗的体液和细胞免疫反应。

DESCRIPTION (provided by investigators): Each year influenza viruses infect 5 to 20% of the US population and cause an annual average of 226,000 hospitalizations and 34,000 deaths. Annual influenza vaccination recommendations traditionally targeted persons aged >65 years; others with medical conditions that also place them at high-risk for influenza- associated complications; and close contacts of those considered "high-risk." These recommendations have recently expanded to include adults aged 50 to 64 years and children aged 6 months to <5 years. These public policy recommendations, which now include the majority of the US population, require careful evaluation to assure that they are having their intended effects. Because influenza viruses and vaccines change annually, annual assessments of vaccine effectiveness are needed. For the past eight years, we have participated in population-based surveillance for influenza in young children with acute respiratory illness in Nashville, Davidson County (population 578,698) as part of the CDC's New Vaccine Surveillance Network. With two years of support from NIH's Vaccine Treatment and Evaluation Unit, we initiated similar surveillance for adults aged >50 years during the 2006-7 influenza season, which will continue through the 2007-8 season. Our experience uniquely qualifies us to efficiently initiate the surveillance activities needed to perform annual assessments of vaccine effectiveness. We have established relationships with Davidson County hospitals that provide care to >95% of county children and >50% of county adults hospitalized with acute respiratory illness. The procedures for enrolling and testing eligible patients have been established, data collection forms developed and field-tested, and laboratory procedures refined and validated. We propose to perform active population-based surveillance for laboratory confirmed influenza in adults and children in order to determine age-specific rates of influenza-associated hospitalizations and emergency department visits in the county. We will work with CDC and other cooperative agreement participants to assess influenza vaccine effectiveness twice annually, once in the middle of influenza season and once at the season's end. We propose a matched case control analysis to assess vaccine effectiveness. Study subjects will be a systematic sample of county children and adults aged 6 months or older with a hospitalization or emergency room visit for acute respiratory illness. Enrolled subjects will contribute nose and throat swabs for influenza testing in the research laboratory. Subjects or their parents/guardians will provide information about their acute illness, medical history, and influenza vaccination status. Cases will be defined by detection of influenza virus by reverse transcriptase- polymerase chain reaction (RT-PCR) or viral culture. All study subjects that test negative for influenza by both RT-PCR and culture will be eligible to be controls. In year one, we also will collect, process, store, and ship to CDC, 450 paired sera and150 paired peripheral blood mononuclear cell specimens to assess both humoral and cellular immune responses to influenza vaccines among adults aged >50 years.