Gans Hayley, DeHovitz Ross, Forghani Bagher, Beeler Judith, Maldonado Yvonne, Arvin Ann M
Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Rm G312, Stanford, CA 94305-5208, USA.
Vaccine. 2003 Jul 28;21(24):3398-405. doi: 10.1016/s0264-410x(03)00341-4.
Evaluations of neutralizing antibody responses in 6-, 9- and 12-month-old infants given measles or mumps vaccine indicated that 6-month-old infants had diminished humoral immune responses associated with passive antibody effects, but also had an intrinsic deficiency in antiviral antibody production, which was independent of passive antibody effects. In contrast, lower neutralizing antibody titers in 9-month-olds were related only to passive antibody effects. Measles and mumps-specific T-cell proliferation and interferon-gamma (IFNgamma) production were induced by vaccination at 6, 9 or 12 months, regardless of passive neutralizing antibodies or age. These observations suggest a need to refine concepts about passive antibody interference and primary vaccine failure, taking into account the sensitization of antiviral T-cells, which occurs in the presence of passive antibodies and is observed in infants who do not develop active humoral immunity. A second dose of measles vaccine given at 12-15 months enhanced antiviral T-cell responses to measles in infants who were vaccinated at 6 or 9 months, and produced higher seroconversion rates. Since T-cell immunity is elicited under the cover of passive antibodies, the youngest infants benefit from the synergistic protection mediated by maternal antibodies and their own capacity to develop sensitized antiviral T-cells, which prime for subsequent exposures to the viral antigens. Conceptually, maternal immunization approaches with vaccines that can be given to women of child-bearing age before pregnancy, or that are safe for administration during pregnancy, should enhance passive antibody protection. Rather than being detrimental to infant adaptive immune responses, maternal vaccination can be coupled effectively with vaccine regimens that elicit priming of antiviral immune responses in infants during the first year of life.
对接种麻疹或腮腺炎疫苗的6个月、9个月和12个月大婴儿的中和抗体反应评估表明，6个月大的婴儿体液免疫反应减弱与被动抗体效应有关，但也存在抗病毒抗体产生的内在缺陷，这与被动抗体效应无关。相比之下，9个月大婴儿较低的中和抗体滴度仅与被动抗体效应有关。无论有无被动中和抗体或年龄大小，在6个月、9个月或12个月接种疫苗均可诱导麻疹和腮腺炎特异性T细胞增殖以及干扰素-γ（IFNγ）产生。这些观察结果表明，需要完善关于被动抗体干扰和原发性疫苗失败的概念，同时考虑抗病毒T细胞的致敏作用，这种致敏作用在被动抗体存在时发生，且在未产生主动体液免疫的婴儿中也可观察到。在12 - 15个月时接种第二剂麻疹疫苗可增强6个月或9个月时接种疫苗的婴儿对麻疹的抗病毒T细胞反应，并产生更高的血清转化率。由于T细胞免疫是在被动抗体的掩护下引发的，最小的婴儿受益于母体抗体介导的协同保护以及自身产生致敏抗病毒T细胞的能力，这些T细胞为后续接触病毒抗原做好准备。从概念上讲，采用可在孕前给予育龄妇女或在孕期安全接种的疫苗进行母体免疫接种方法，应能增强被动抗体保护作用。母体接种疫苗并非对婴儿适应性免疫反应有害，反而可与在婴儿出生后第一年引发抗病毒免疫反应的疫苗接种方案有效结合。
