OBJECTIVES To determine the effectiveness of influenza vaccination during pregnancy on child health outcomes. DESIGN Systematic review/meta-analysis. DATA SOURCES Clinical Trials.gov, Cochrane Library, EMBASE, Medline, Medline in process, PubMed and Web of Science, from 1st January 1996 to 29th June 2018. An updated Medline search was performed 30th June 2018 to 31st October 2019. METHODS Randomised controlled trials (RCTs) and observational studies reporting health outcomes of infants and children born to women who received inactivated influenza vaccine during pregnancy. The primary outcome was infant laboratory confirmed influenza (LCI). Secondary outcomes included influenza-like illness (ILI), other respiratory illnesses, primary care, clinic visit or hospitalisations due to influenza illness and long-term respiratory childhood outcomes. RESULTS 19 studies were included; 15 observational studies and 4 primary RCTs with an additional 3 papers reporting secondary outcomes of these RCTs. In a random effects meta-analysis of 2 RCTs including 5742 participants, maternal influenza vaccination was associated with an overall reduction of LCI in infants of 34% (95% confidence interval 15-50%). However, there was no effect of maternal influenza vaccination on ILI in infants ≤6 months old. Two RCTs were excluded from the meta-analysis for the outcome of LCI in infants (different controls used). Both of these studies showed a protective effect for infants from LCI, with a vaccine efficacy of up to 70%. Overall observational studies showed an inverse (protective) association between maternal influenza vaccination and infant LCI, hospitalisation and clinic visits due to LCI or ILI in infants and other respiratory illness in infants ≤6 months old. CONCLUSIONS This systematic review supports maternal influenza vaccination as a strategy to reduce LCI and influenza-related hospitalisations in young infants. Communicating these benefits to pregnant women may support their decision to accept influenza vaccination in pregnancy and increase vaccine coverage in pregnant women. REGISTRATION PROSPERO CRD42018102776.

中文翻译：

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与儿童健康状况相关的妊娠期流感疫苗接种的有效性：系统评价和荟萃分析。

目的确定怀孕期间接种流感疫苗对儿童健康结局的有效性。设计系统评价/元分析。数据来源：Clinical Trials.gov，Cochrane图书馆，EMBASE，Medline，Medline在进行中，PubMed和Web of Science，时间为1996年1月1日至2018年6月29日。Medline的最新搜索时间为2018年6月30日至2019年10月31日。方法随机对照试验（RCT）和观察性研究报告了在怀孕期间接受灭活流感疫苗的妇女所生婴儿和儿童的健康结局。主要结局是婴儿实验室确诊的流感（LCI）。次要结局包括流感样疾病（ILI），其他呼吸道疾病，初级保健，诊所就诊或因流感病和长期呼吸道童年结局而住院。结果共纳入19项研究。15项观察性研究和4项主要RCT，另有3篇论文报告了这些RCT的次要结果。在一项包括5742名参与者的2个RCT的随机效应荟萃分析中，母亲流感疫苗接种与婴儿LCI总体降低34％（95％置信区间15-50％）有关。但是，母亲流感疫苗接种对6个月以下婴儿的ILI没有影响。荟萃分析排除了两个针对婴儿LCI结果的RCT（使用了不同的对照）。这两项研究均显示对LCI婴儿具有保护作用，疫苗效力高达70％。整体观察性研究显示，母亲流感疫苗接种与婴儿LCI之间存在反向（保护性）关联，LCI或ILI导致的住院和诊所就诊以及6个月以下婴儿的其他呼吸系统疾病。结论这项系统评价支持母体流感疫苗接种作为减少幼儿LCI和与流感相关的住院治疗的策略。向孕妇传达这些好处可能会支持他们决定在怀孕时接受流感疫苗接种并增加孕妇的疫苗覆盖率。注册PROSPERO CRD42018102776。向孕妇传达这些好处可能会支持他们决定在怀孕时接受流感疫苗接种并增加孕妇的疫苗覆盖率。注册PROSPERO CRD42018102776。向孕妇传达这些好处可能会支持他们决定在怀孕时接受流感疫苗接种并增加孕妇的疫苗覆盖率。注册PROSPERO CRD42018102776。