Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
Vaccine. 2012 Feb 21;30(9):1541-59. doi: 10.1016/j.vaccine.2011.12.047. Epub 2011 Dec 18.
Many serious infectious diseases occur early in life; efficacious vaccination of neonates has been a longstanding goal in both human and veterinary medicine. Efforts to immunize in the first weeks of life, in various species, have had limited success in general. This has been attributed to a combination of immaturity of the neonatal immune system and interference by maternal antibodies. Most studies of neonatal immune responsiveness have been carried out in neonatal mice, or by examination of cellular components of human umbilical cord blood. Both approaches have their limitations. The current review describes factors, including corticosteroids, complement proteins, cytokines, maternal lymphocytes and antibodies, which may influence immune responses of neonates, comparing data from studies of domestic animals and humans. Neonates are highly dependent on passive (maternal) antibodies for protection against a wide range of pathogens. These maternal antibodies have been noted to interfere with active immune responses to many, but not all, vaccines. Various theories have been proposed to explain this phenomenon, including epitope masking, clearance of immune complexes and FcγRII mediated regulation of B cells. Remarkably, many studies examining the effects of passive antibodies on immune responses of adults, have demonstrated immune enhancing effects. The evidence for enhancing and suppressive effects of passive antibodies on antigen uptake, processing and regulation of lymphocyte responses is reviewed. Since maternal antibodies (as present in neonates) differ in subisotypes and affinity from the passive antibodies often used in experimental systems, here is a need for better experimental models investigating the effects of bona fide maternal antibodies on immune responses of neonates (not adult surrogates). Vaccines can be optimized for use in neonates - by making better use of existing vaccine technologies and by harnessing the potential of recent immunological and technological advances.
许多严重的传染病发生在生命早期；在人类和兽医医学中，对新生儿进行有效疫苗接种一直是一个长期目标。在各种物种中，在生命的最初几周内进行免疫接种的努力总体上收效有限。这归因于新生儿免疫系统的不成熟和母体抗体的干扰。大多数关于新生儿免疫反应的研究都是在新生小鼠中进行的，或者通过检查人类脐带血的细胞成分来进行。这两种方法都有其局限性。本综述描述了包括皮质类固醇、补体蛋白、细胞因子、母体淋巴细胞和抗体在内的各种因素，这些因素可能会影响新生儿的免疫反应，同时比较了来自家畜和人类研究的数据。新生儿高度依赖母体抗体被动保护免受广泛病原体的侵害。已经注意到这些母体抗体会干扰对许多但不是所有疫苗的主动免疫反应。已经提出了各种理论来解释这种现象，包括表位掩盖、免疫复合物清除和 FcγRII 介导的 B 细胞调节。值得注意的是，许多研究检查了被动抗体对成人免疫反应的影响，证明了免疫增强作用。本文综述了被动抗体对抗原摄取、加工和调节淋巴细胞反应的免疫增强和抑制作用的证据。由于母体抗体（如新生儿中的）在亚类和亲和力上与实验系统中常用的被动抗体不同，因此需要更好的实验模型来研究真正的母体抗体对新生儿免疫反应的影响（而不是成年替代物）。可以通过更好地利用现有疫苗技术并利用最近免疫学和技术进步的潜力，优化疫苗在新生儿中的使用。
