A Randomised Controlled Trial of the Effectiveness of Vaccinating Children to Reduce Household Transmission of Influenza
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 2,800
- 试验地点
- 1
- 主要终点
- The proportions of subjects and household contacts with serology-confirmed influenza infection during follow-up among the 2 intervention arms.
研究概览
简要总结
While immunisation of school-age children against influenza is not recommended in Hong Kong, past experience in Japan and elsewhere suggests that immunisation of children may protect the wider community through its indirect transmission-limiting impact as well as the direct immunologic protection afforded vaccinated children themselves. We aim to assess whether vaccinating children against influenza protects vaccinees as well as their household contacts from infection.
详细描述
Design and subjects: A double-blind randomised controlled trial of 800 subjects aged 6-17 drawn from the general population and their 2000 household contacts. The subjects will be randomised in a 3:2 ratio to the intervention and placebo groups, respectively. Serum samples will be collected from subjects pre- and 1 month post-vaccination, and after the influenza season. Serum samples will be collected from household contacts at baseline and at the end of the influenza season. During the follow-up period, subjects and household members will keep symptom diaries and those reporting influenza-like-illness will be offered free doctor consultations or home visits where we will arrange for collection of nose and throat swabs.
Study instruments: An antibody titre of ≥40 in the post-vaccine serum will be used to define seroprotection to those particular strains, while a four-fold or higher increase in antibody titres between baseline and end-of-season follow-up of the household contacts will define influenza infection during the season. Subjects and household contacts will be asked to keep symptom diaries, and during episodes of ILI we will collect nose and throat swabs for laboratory confirmation of influenza infection; the primary serology results will then be compared with clinical and laboratory-confirmed influenza episodes.
Interventions: 1 (intervention) inactivated influenza vaccine (Vaxigrip, Sanofi Pasteur); 2 (placebo) saline injection.
Main outcome measures: The proportions of subjects and household contacts with serology-confirmed influenza infection during follow-up among the 2 intervention arms.
Analysis: Intention to treat, adjusting for within-household correlation in influenza attack rates.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- Triple (Participant, Care Provider, Outcomes Assessor)
入排标准
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •All vaccinees must be Hong Kong residents aged between 6 and 17.
排除标准
- •Vaccinees should not be allergic or hypersensitive to the active substances or components (eggs, chicken proteins, formaldehyde, neomycin, etc.) used in the vaccines or where vaccination is otherwise contraindicated. Subjects should not have an underlying immunocompromised condition or be receiving immunosuppressive agents.
研究组 & 干预措施
1
Influenza vaccine
干预措施: Inactivated influenza vaccine (Biological)
2
干预措施: Saline (Biological)
结局指标
主要结局
The proportions of subjects and household contacts with serology-confirmed influenza infection during follow-up among the 2 intervention arms.
时间窗: nine months
次要结局
未报告次要终点