孕产妇流感及疫苗的流行病学研究进展

Progress in epidemiological research of influenza and vaccine in pregnant women

流行性感冒(以下简称“流感”)每年呈季节性流行,孕妇作为流感的高危人群,感染后更易发展为严重疾病及并发症,也可对胎儿和新生儿产生不良影响。我国研究提示,孕妇对流感普遍易感,与一般健康育龄女性相比,孕妇出现严重疾病的风险增加至3.3倍[95%CI(2.7,4.0)]。妊娠女性感染流感可导致不良妊娠及分娩结局的发生,主要表现在住院患者中,特别是患有重症流感的妊娠女性。国外多项研究证实,孕前或孕期免疫接种流感疫苗可以起到明显的预防效果,妊娠期接种流感疫苗可降低其自身和新生儿流感发病率和死亡率。流感疫苗接种对妊娠结局也具有一定的保护作用,可降低母体发生流感感染相关胎盘早剥、早产、低出生体重和小于胎龄儿等风险。国际上大量的临床试验、观察性研究、疫苗上市后不良反应报告系统数据和相关临床指南均证实孕妇接种流感疫苗的安全性,但该人群流感疫苗的接种率一直很低,主要影响因素包括对流感及疫苗认知态度、既往疫苗接种行为、付费意愿以及卫生保健专业人员的推荐等。我国尚缺乏孕妇流感疫苗接种安全性评价的数据,部分流感疫苗产品说明书仍将孕产妇列为禁忌证。本文对孕产妇流感的流行特征及疫苗的流行病学研究进行综述,为相关防控政策制定及研究等提供科学依据。

Influenza,also known as the flu,spreads in a seasonal pattern annually.Pregnant women are at high risk of influenza infection and are more likely to develop into severe illness and complications after infection.Influenza infection can also lead to adverse effects on the fetus and newborn.Studies in China suggest that pregnant women are generally susceptible to influenza.The risk of developing serious disease in pregnant women increased to 3.3 times(95%CI 2.7 to 4.0)compared with normal healthy women of childbearing age.Influenza infection in pregnant women is related to adverse pregnancy and delivery outcomes,mainly in hospitalized patients,particularly pregnant women with severe influenza.Numbers of foreign studies have confirmed that influenza vaccination during or before pregnancy can provide protective effect against flu,and vaccination during pregnancy can reduce the morbidity of influenza infection and mortality in pregnant women and their infants.Influenza vaccination also provides protection on maternal-fetal outcomes,reduces the risk associated with influenza infection such as placental abruption,preterm birth,low birth weight,small for gestational age infants and so on.Although a large number of international clinical trials,observational studies,data from post-marketing adverse events reporting system and related clinical guidelines have confirmed the safety of influenza vaccination in pregnant women,the coverage rate of influenza vaccine in this population remains low and the determinants mainly include cognitive attitudes towards influenza and the influenza vaccine,vaccination history,willingness to pay for the influenza vaccine and recommendations from healthcare professionals.The data of the safety evaluation of influenza vaccination for pregnant women is insufficient in China.Some influenza vaccine package instructions still list pregnancy as contraindications.This study reviews the epidemiological characteristics of influenza in pregnant women and epidemiological studies on influenza vaccines to provide scientific evidence for the formulation of relevant prevention and control policies and related research.