Mucosal Infection and Immunity Group, Section of Virology, Department of Medicine, St Mary's Campus, Imperial College London, UK.
Centre for International Child Health, Section of Paediatrics, Department of Medicine, St Mary's Campus, Imperial College London, UK.
Clin Exp Immunol. 2019 Feb;195(2):139-152. doi: 10.1111/cei.13234. Epub 2018 Dec 2.
Pregnant women and infants are at an increased risk of severe disease after influenza infection. Maternal immunization is a potent tool to protect both these at-risk groups. While the primary aim of maternal influenza vaccination is to protect the mother, a secondary benefit is the transfer of protective antibodies to the infant. A recent study using the tetanus, diphtheria and acellular pertussis (Tdap) vaccine indicated that children born to mothers immunized in the second trimester of pregnancy had the highest antibody titres compared to children immunized in the third trimester. The aim of the current study was to investigate how the timing of maternal influenza immunization impacts infant antibody levels at birth. Antibody titres were assessed in maternal and cord blood samples by both immunoglobulin (Ig)G-binding enzyme-linked immunosorbent assay (ELISA) and haemagglutination inhibition assay (HAI). Antibody titres to the H1N1 component were significantly higher in infants born to mothers vaccinated in either the second or third trimesters than infants born to unvaccinated mothers. HAI levels in the infant were significantly lower when maternal immunization was performed less than 4 weeks before birth. These studies confirm that immunization during pregnancy increases the antibody titre in infants. Importantly, antibody levels in cord blood were significantly higher when the mother was vaccinated in either trimesters 2 or 3, although titres were significantly lower if the mother was immunized less than 4 weeks before birth. Based on these data, seasonal influenza vaccination should continue to be given in pregnancy as soon as it becomes available.
孕妇和婴儿在流感感染后患重病的风险增加。孕产妇免疫是保护这两个高危人群的有力工具。虽然母亲流感疫苗接种的主要目的是保护母亲，但次要益处是将保护性抗体转移给婴儿。最近一项使用破伤风、白喉和无细胞百日咳（Tdap）疫苗的研究表明，与第三孕期接种疫苗的婴儿相比，第二孕期接种疫苗的母亲所生的婴儿抗体滴度最高。本研究旨在探讨母亲流感免疫接种的时间如何影响婴儿出生时的抗体水平。通过免疫球蛋白（IgG）结合酶联免疫吸附试验（ELISA）和血凝抑制试验（HAI）评估母血和脐血样本中的抗体滴度。与未接种疫苗的母亲所生婴儿相比，在第二或第三孕期接种疫苗的母亲所生婴儿的 H1N1 组分抗体滴度显著更高。当母亲在分娩前不到 4 周进行免疫接种时，婴儿的 HAI 水平显著降低。这些研究证实，怀孕期间的免疫接种会增加婴儿的抗体滴度。重要的是，当母亲在第 2 或第 3 孕期接种疫苗时，脐带血中的抗体水平显著升高，尽管如果母亲在分娩前不到 4 周接种疫苗，抗体滴度会显著降低。基于这些数据，一旦流感疫苗在孕期可用，就应继续在孕期接种。
