IMMUNOGENICITY OF MEASLES VIRUS VACCINE STRAINS

USPHS的主要目标之一是在区域内消除 到2000年麻疹。 过去已经取得了重大进展 在美国，由于免疫接种率的提高， 实施含麻疹疫苗的两剂接种计划。 然而，关于最佳使用， 麻疹疫苗。 例如，第二剂的优选年龄 麻疹疫苗是未知的。 为了比较麻疹 4-5岁接种疫苗，11-12岁免疫， 威斯康星州的1800名儿童接种了第二剂麻疹疫苗 疫苗 比较1个月和6个月的中和抗体滴度 免疫后。 所有血清阴性儿童均成功 接种麻疹疫苗。 4-5岁接种疫苗的儿童 中和抗体滴度>900（84%）的儿童 在11-12岁接种疫苗。 目前正在进行后续研究 看看这些差异是否会持续下去。 这些发现表明， 麻疹第二剂的主要效果是减少人口 一次疫苗接种失败的儿童。 几乎没有助推器 观察到效果，推迟免疫接种没有好处， 青春期 涉及麻疹疫苗安全性的两个问题是 研究了 据报告，麻疹疫苗受到瘟病毒污染 在日本 为了了解其他麻疹和病毒疫苗是否含有 瘟病毒序列，我们使用PCR筛选BVDV和HCV。 一 实验疫苗对BVDV序列呈阳性，而所有其他 病毒疫苗测试结果呈阴性反应。 麻疹的使用 含有疫苗也可能与免疫后免疫有关 血小板减少症 为了确定免疫后的原因 血小板减少症，我们已经开始了一项研究，以确定疫苗 负责诱导抗血小板抗体的组分 MMR免疫。

One of the major goals of the USPHS is the regional elimination of measles by the year 2000. Significant progress has been made in the past few years in the US due to an increase in immunization rates and implementation of a two dose schedule for measles containing vaccines. However, there are still some unanswered questions regarding optimal use of measles vaccines. For example, the preferred age for the second dose of measles vaccine was not known. In order to compare measles vaccination at 4-5 years of age with immunization at 11-12 years of age, 1800 children in Marshfied, Wisconsin received dose two of measles vaccine. Neutralizing antibody titers wer compared one and 6 months after immunization. All seronegative children were successfully immunized against measles. Children immunized at 4-5 years were more likely to achieve neutralizing antibody titers >900 (84%) than children immunized at 11-12 years of age. A follow-up study is curretly underway to see if these differences persist. These finding suggest that the primary effect of the measles second dose is to decrease the population of children with primary vaccine failure. There was little booster effect observed and no benefit derived to postponing immunization until adolescence. Two issues involved with the safety of measles vaccine were studied. Pestivirus contamination of measles vaccines had been reported in Japan. In order to see if other measles and viral vaccines contained pestivirus sequences we used PCR to screen for BVDV and HCV. One experimental vaccine was positive for BVDV sequences while all other viral vaccines tested were found to be negative. The use of measles containing vaccines may also be associated with post immunization immune thrombocytopenia. In order to determine the cause of post immunization thrombocytopenia, we have initiated a study to identify vaccine component(s) responsible for inducing anti-platelet antibodies after immunization with MMR.