UMR VITROME, Institut de Recherche Pour le Développement, Dakar, Senegal.
Institut Pasteur de Dakar, Senegal.
Clin Infect Dis. 2019 Oct 30;69(10):1780-1788. doi: 10.1093/cid/ciz066.
The population effects of influenza vaccination in children have not been extensively studied, especially in tropical, developing countries. In rural Senegal, we assessed the total (primary objective) and indirect effectiveness of a trivalent inactivated influenza vaccine (IIV3).
In this double-blind, cluster-randomized trial, villages were randomly allocated (1:1) for the high-coverage vaccination of children aged 6 months through 10 years with either the 2008-09 northern hemisphere IIV3 or an inactivated polio vaccine (IPV). Vaccinees were monitored for serious adverse events. All village residents, vaccinated and unvaccinated, were monitored for signs and symptoms of influenza illness using weekly home visits and surveillance in designated clinics. The primary outcome was all laboratory-confirmed symptomatic influenza.
Between 23 May and 11 July 2009, 20 villages were randomized, and 66.5% of age-eligible children were enrolled (3918 in IIV3 villages and 3848 in IPV villages). Follow-up continued until 28 May 2010. There were 4 unrelated serious adverse events identified. Among vaccinees, the total effectiveness against illness caused by the seasonal influenza virus (presumed to all be drifted A/H3N2, based on antigenic characterization data) circulating at high rates among children was 43.6% (95% confidence interval [CI] 18.6-60.9%). The indirect effectiveness against seasonal A/H3N2 was 15.4% (95% CI -22.0 to 41.3%). The total effectiveness against illness caused by the pandemic influenza virus (A/H1N1pdm09) was -52.1% (95% CI -177.2 to 16.6%).
IIV3 provided statistically significant, moderate protection to children in Senegal against circulating, pre-2010 seasonal influenza strains, but not against A/H1N1pdm09, which was not included in the vaccine. No indirect effects were measured. Further study in low-resource populations is warranted.
NCT00893906.
流感疫苗在儿童人群中的人群效应尚未得到广泛研究，尤其是在热带发展中国家。在塞内加尔农村，我们评估了三价灭活流感疫苗（IIV3）的总体（主要目标）和间接效力。
在这项双盲、整群随机试验中，将村庄以 1:1 的比例随机分配给接种组（接种组）和对照组（接种灭活脊髓灰质炎疫苗，IPV），为 6 个月至 10 岁的儿童进行高覆盖率的疫苗接种。接种者监测严重不良事件。所有村庄居民，无论是否接种疫苗，均通过每周家访和指定诊所监测来监测流感样疾病的症状和体征。主要结局是所有实验室确诊的有症状流感。
2009 年 5 月 23 日至 7 月 11 日期间，20 个村庄被随机分组，符合年龄要求的儿童中有 66.5%（IIV3 组 3918 人，IPV 组 3848 人）入组。随访持续到 2010 年 5 月 28 日。确定了 4 例无关的严重不良事件。在疫苗接种者中，针对高流行率儿童季节性流感病毒（假定为所有漂移的 A/H3N2，基于抗原特征数据）引起的疾病的总效力为 43.6%（95%置信区间 [CI] 18.6-60.9%）。针对季节性 A/H3N2 的间接效力为 15.4%（95% CI -22.0 至 41.3%）。针对大流行流感病毒（A/H1N1pdm09）的总效力为-52.1%（95% CI -177.2 至 16.6%）。
在塞内加尔，IIV3 为儿童提供了针对循环的、2010 年前季节性流感株的具有统计学意义的中度保护，但对 A/H1N1pdm09 无效，该病毒未包含在疫苗中。未测量到间接效应。需要在资源匮乏的人群中进一步研究。
NCT00893906。
