Executive Board of the Allineare Sanità e Salute Foundation , Milano , Italy.
Hum Vaccin Immunother. 2019;15(9):2159-2164. doi: 10.1080/21645515.2019.1568161. Epub 2019 Feb 20.
Pregnant women are a WHO priority group for influenza vaccination, but evidence from observational studies in pregnancy is subject, among others, to the healthy-vaccinee bias, overestimating the vaccine effectiveness and safety. An USA survey adds new evidence that documents this bias. Therefore, it is essential to assess vaccine effectiveness and safety with RCTs. Cochrane reviews identified one RCT with "low risk of bias", in a medium-income country, with NNV 55 for mothers. Its data show an excess of local adverse effects, and a tendency to harm for serious adverse events, with uncertain or very limited protection against influenza. A subsequent larger trial in a very-low-income African country found an excess of infant serious infections plus deaths in the influenza vaccine group. Also an available previous small trial and a subsequent large one in Asian low-income countries showed in tendency more deaths in the offspring vaccine groups. Before promoting seasonal influenza vaccinations during all pregnancies, more independent trials are needed, with appropriate designs and comparators. Meanwhile, vaccination in second-third trimester could be offered communicating the uncertainties and promoting informed choices, without neglecting to promote other protective behaviors.
孕妇是世界卫生组织流感疫苗接种的重点人群，但来自妊娠观察性研究的证据除其他外，还存在健康接种者偏倚，高估了疫苗的有效性和安全性。美国的一项调查增加了新的证据，证明了这种偏见的存在。因此，使用 RCT 评估疫苗的有效性和安全性至关重要。Cochrane 综述确定了一项在中等收入国家进行的“低偏倚风险” RCT，母亲的 NNV 为 55。其数据显示局部不良反应过多，严重不良事件有损害趋势，对流感的保护不确定或非常有限。随后在一个非常低收入的非洲国家进行的一项更大规模的试验发现，流感疫苗组婴儿严重感染和死亡的病例过多。另外，之前的一项小型试验和之后在亚洲低收入国家进行的一项大型试验也显示，疫苗组的后代死亡病例有增加的趋势。在推广所有妊娠期间季节性流感疫苗接种之前，需要进行更多独立的试验，采用适当的设计和对照。同时，可以在第二和第三孕期提供疫苗接种，同时告知不确定性并促进知情选择，同时不要忽视促进其他保护行为。
