Seasonal Influenza Vaccine Effectiveness in a Tropical Developing African Country

热带非洲发展中国家季节性流感疫苗的有效性

• 批准号: 8335176
• 负责人: John Christian Victor
• 金额: $ 125万
• 依托单位: PATH
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-30 至 2014-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8335176
• 关键词: Seasonal; Influenza; Vaccine; Effectiveness; Tropical

PROJECT SUMMARY Influenza is a major cause of morbidity and mortality nearly every year; when pandemics occur, the impact is even more severe. A pandemic virus may result from reassortment of human influenza viruses with animal influenza viruses. Such reassortment may occur more readily in tropical climates where human and animal viruses frequently co-circulate throughout the year. Few data are available to document the transmission and burden of influenza in tropical developing countries. Without a better understanding of influenza epidemiology in such situations, it is difficult for national and global public health officials to develop influenza-control strategies for either seasonal or pandemic influenza. Effective inactivated influenza vaccines have been available for decades, but data are lacking on their effectiveness for both protecting recipients in tropical developing countries and also their ability to reduce transmission in such populations. A number of reports from developed countries indicate that influenza vaccine, when given to a limited number of persons most responsible for transmission, usually children, has the potential to interrupt transmission and reduce the overall influenza burden in a community. The potential of influenza vaccine to provide indirect protection to unvaccinated individuals suggests that targeted use, which may be feasible in developing-country settings, might reduce influenza infection in the community beyond those who were vaccinated. In a pandemic situation, these efforts could slow the spread of pandemic virus and provide sufficient time for public health officials to introduce interventions to contain or blunt the effects of a pandemic. Thus, to evaluate the effectiveness of trivalent, inactivated influenza vaccine in a tropical developing country, we propose to conduct an observer- blind, cluster-randomized, controlled, parallel-group trial of a new adjuvanted influenza vaccine in Senegal. The trial will take place over a three-year period and will target children 6 months to 10 years of age for vaccination. Not only will effectiveness be estimated for child vaccine recipients, but indirect effectiveness will also be measured for the rest of the community. Throughout the course of the study, both sentinel and active surveillance will be conducted to document the occurrence of febrile acute respiratory illness among participants and in the community. The primary outcome will be prevention of symptomatic laboratory- confirmed influenza meeting a case definition. Surveillance will also allow us to describe the epidemiology of influenza in a tropical developing country by defining the rates of laboratory-confirmed influenza and by describing the clinical characteristics of influenza in the population.

项目摘要 流感几乎每年都是发病和死亡的主要原因;当大流行发生时，其影响是 甚至更严重。大流行病毒可能是由人流感病毒与动物流感病毒的重配引起的 流感病毒。在热带气候中，人类和动物 病毒经常在全年共同传播。几乎没有数据可以证明这种传播， 热带发展中国家的流感负担。如果没有更好地了解流感流行病学 在这种情况下，国家和全球公共卫生官员很难制定流感控制措施 应对季节性或大流行性流感的战略。有效的灭活流感疫苗已经 几十年来一直可用，但缺乏关于其对保护热带地区接受者的有效性的数据。 发展中国家以及它们减少此类人群传播的能力。一些报告 来自发达国家的研究表明，流感疫苗，当给予有限数量的人， 负责传播的人，通常是儿童，有可能中断传播并减少总体感染。 社区的流感负担。流感疫苗提供间接保护的潜力 未接种疫苗的个人表明，有针对性的使用，这可能是可行的，在发展中国家的环境， 可能会减少社区中接种疫苗者以外的流感感染。在大流行的情况下， 这些努力可以减缓大流行病毒的传播，并为公共卫生官员提供足够的时间， 采取干预措施以控制或减弱大流行病的影响。因此，为了评估 三价灭活流感疫苗，我们建议进行观察员- 在塞内加尔进行的一项新的含佐剂流感疫苗的盲法、随机分组、对照、平行组试验。的 试验将在三年内进行，对象是6个月至10岁的儿童。 不仅将评估儿童疫苗接种者的有效性，还将评估间接有效性。 为社区的其他人衡量。在整个研究过程中，无论是哨兵还是主动 将进行监测，以记录下列人员中发热性急性呼吸道疾病的发生情况： 参与者和社区。主要结果将是预防症状性实验室- 符合病例定义的确诊流感。监测还将使我们能够描述 通过定义实验室确诊流感的比率， 描述人群中流感的临床特征。