IMMUNOGENICITY OF MEASLES VIRUS VACCINE STRAINS

麻疹暴发继续发生在未接种疫苗的儿童和年龄较大的人中。 由于初级疫苗失败或免疫力减弱而接种的疫苗。实现 所有年龄段的保护性免疫需要几种策略 包括更好地理解为年轻人接种疫苗的最佳年龄 婴儿，再免疫的最佳年龄，以及关于 可能增强或减弱对当前的反应的因素 可用的疫苗。为此，该实验室与 几位临床研究人员评估麻疹的免疫反应 疫苗。在亨利·帕布斯特博士的合作下，我们已经完成了 定义体液免疫和细胞免疫动力学的研究 12个月龄婴儿首次接种麻疹疫苗的免疫应答 孩子们。80名儿童接种了含有莫拉坦的疫苗 麻疹病毒株，连续随访38天。中和 麻疹HA抗体和CMI反应在28天后趋于平稳 免疫接种。对破伤风和念珠菌的淋巴增殖反应 在免疫后14天抑郁，但白天恢复到基线 38.对召回抗原的反应抑制了10%-20%；相比之下， 野生型感染后80%-90%的反应被抑制。这个 免疫后PBMC表达的主要细胞因子为干扰素-γ 白介素4或白介素10的分泌没有变化表明原发麻疹 以TH1型为主的免疫原点。其影响 补充维生素A对麻疹初级免疫的影响(施瓦茨) 菌株)在9个月内进行了安慰剂对照的双盲试验 印度尼西亚的老婴儿与理查德·桑巴博士合作。那里 在维生素处理组和对照组之间没有显著差异 血清转换率或达到保护性的百分比 中和抗体滴度。然而，安慰剂中婴儿的GMT 在免疫时有母源抗体的组较高 比GMTS中抗体阳性的婴儿在接受维生素a治疗时 研究小组认为被动获得的抗体和维生素之间存在协同作用 在限制疫苗病毒复制方面。进行研究以评估 目前接种第二针麻疹疫苗的最佳年龄是 正在进行中。237例儿童血清检测结果初步分析 标志着第二针麻疹疫苗在#年成功 所有初级疫苗失败并增加的儿童血清转换 效价&gt；120的百分比从94%到99%。这种级别的免疫力是 在美国实现根除麻疹所必需的。

Measles outbreaks continue to occur in unimmunized children and in older vaccines due to primary vaccine failure or waning immunity. Achieving protective immunity across all age groups requires several strategies including a better understanding of the optimal age for immunizing young infants, the optimal age for reimmunization, and knowledge about the factors that might enhance or diminish the response to currently available vaccines. Towards this end, this laboratory collaborates with several clinical investigators to evaluate the immune response to measles vaccine. In collaboration with Dr. Henry Pabst, we have completed studies that define the kinetics of the humoral and cell mediated immune response to the first dose of measles containing vaccine in 12 month old children. 80 children were immunized with vaccine containing the Moraten strain of measles virus and followed serially for 38 days. Neutralizing antibody and CMI response to measles HA plateaued by 28 days after immunization. Lymphoproliferative responses to tetanus and candida were depressed at 14 days after immunization but returned to baseline by day 38. The response to recall antigens were depressed 10-20%; in contrast, responses were depressed 80-90% following wild type infection. The predominant cytokine expressed by PBMCs after immunization was IFN-gamma with no change in IL4 or IL10 secretion suggesting that primary measles immunization primes for a predominantly TH1 type response. The impact of vitamin A supplementation on primary measles immunization (Schwarz strain) was studied in a placebo controlled double-blind trial in 9 month old infants in Indonesia in collaboration with Dr. Richard Semba. There was no significant difference between the vitamin treated and control groups in seroconversion rates or percent achieving protective neutralizing antibody titers. However, GMTs for infants in the placebo group who had maternal antibody at the time of immunization were higher than the GMTs for antibody positive infants in the vitamin a treated group suggesting synergy between passively acquired antibody and vitamin A in limiting vaccine virus replication. Studies to evaluate the optimal age for the second dose of measles vaccine are currently underway. Preliminary analysis of sera from over 237 children indicates that the second dose of measles vaccine is successful in seroconverting all children with primary vaccine failure and increases the percent with titers >120 from 94 to 99%. This level of immunity is necessary to achieve measles eradication in the US.