Center for Vaccine Development, University of Maryland, Baltimore.
International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka.
Clin Infect Dis. 2017 Nov 13;65(11):1914-1920. doi: 10.1093/cid/cix674.
Influenza causes substantial morbidity in children worldwide, although influenza vaccine is seldom used in low-resource settings. More information on the clinical presentation of influenza and the efficacy of vaccine is needed to inform policy.
In 2013 we conducted a randomized, placebo-controlled clinical trial of live attenuated influenza vaccine (LAIV) in children aged 24-59 months in Bangladesh (N = 1761). If participants met prespecified specimen collection criteria, we collected nasopharyngeal washes for testing by singleplex reverse-transcription polymerase chain reaction (RT-PCR) for laboratory-confirmed influenza virus infection (LCI). A panel of RT-PCR assays was used to detect noninfluenza respiratory viruses. Primary efficacy results have been reported. In this analysis of prespecified and post hoc objectives from the trial, we compared signs and symptoms between LCI and non-LCI cases and estimated the efficacy of LAIV against moderate-to-severe LCI and other prespecified non-LCI clinical outcomes including all-cause pneumonia and acute otitis media.
The most common signs and symptoms of LCI were fever, cough, and runny nose. The combination of subjective fever and cough had a 63% sensitivity for LCI. The combination of measured fever, cough, and runny nose was most specific (90%) but had low sensitivity (32%) for LCI. The efficacy of LAIV against vaccine-strain moderate-to-severe LCI was 56.7% (95% confidence interval, 9.5%-79.2%). No statistically significant vaccine efficacy was found against the non-laboratory-confirmed clinical outcomes.
It was not possible to distinguish LCI from noninfluenza viral infections on clinical evaluations alone in this population of Bangladeshi children. LAIV was efficacious against moderate-to-severe LCI.
NCT01797029.
流感在全球范围内会导致大量儿童发病，但在资源匮乏的环境中，流感疫苗的使用却很少见。为了制定相关政策，我们需要更多关于流感临床症状和疫苗效果的信息。
2013 年，我们在孟加拉国开展了一项随机、安慰剂对照临床试验，研究对象为 24-59 月龄的儿童（共 1761 名），接种减毒活流感疫苗（LAIV）。如果参与者符合规定的样本采集标准，我们将通过单重实时逆转录聚合酶链反应（RT-PCR）采集鼻咽冲洗液，以检测实验室确诊的流感病毒感染（LCI）。我们使用了一组 RT-PCR 检测试剂盒来检测非流感呼吸道病毒。此前已报告了主要疗效结果。在这项对试验中预先设定和事后目标的分析中，我们比较了 LCI 与非 LCI 病例之间的体征和症状，并估计了 LAIV 对中重度 LCI 和其他预先设定的非 LCI 临床结局（包括所有病因肺炎和急性中耳炎）的疗效。
LCI 最常见的体征和症状是发热、咳嗽和流涕。主观发热伴咳嗽对 LCI 的敏感性为 63%。而发热、咳嗽和流涕同时存在的组合对 LCI 最具特异性（90%），但敏感性较低（32%）。LAIV 对疫苗株中重度 LCI 的疗效为 56.7%（95%置信区间，9.5%-79.2%）。但针对非实验室确诊的临床结局，未发现 LAIV 有统计学显著的疗效。
在孟加拉国的儿童人群中，仅凭临床评估无法区分 LCI 与非流感病毒感染。LAIV 对中重度 LCI 有效。
NCT01797029。
