轮状病毒减毒活疫苗免疫原性及影响因素研究

发布时间：2018-06-08 02:52

本文选题：轮状病毒疫苗 + 免疫原性　；参考：《北京协和医学院》2016年博士论文

【摘要】：轮状病毒(Rotavirus,RV)是导致世界范围婴幼儿重症腹泻的主要病原体之一,轮状病毒感染被称为“民主病”,无论发达还是发展中国家儿童都会感染,给世界各国带来了严重的社会和经济负担。但在发展中国家引起的5岁以下儿童死亡率更高。疫苗接种是唯一预防轮状病毒腹泻,降低死亡率的有效途径。近十年来,葛兰素史克公司生产的人类轮状病毒减毒活疫苗(Rotarix)和默沙东公司生产的口服轮状病毒五价活疫苗(RotaTeq)在世界范围广泛使用。疫苗临床试验和上市后调查数据显示轮状病毒减毒活疫苗在发达国家具有高效的保护作用,然而在最需要它们的发展中国家,疫苗的有效性和免疫原性却不理想。对于这种现象,亟待找出原因以提高轮状病毒疫苗在发展中国家的有效性。学者们针对此现象曾经进行过研究,从接种者的营养状况、肠道菌群、母乳喂养行为以及病毒株流行的不同入手,解释免疫原性差异的原因。但这些阐述综合起来分析并不能够给出全面系统合理的解释,也有待于从不同侧面进行更深入的研究。免疫系统具有复杂的网络结构,导致轮状病毒疫苗在不同地区免疫原性和有效性不同的也可能不仅限于上述几个因素。鉴于此,本研究从接种者机体内免前母传抗体、人类白细胞抗原(Human Leukocyte Antigen, H LA)基因多态性和同时接种口服脊髓灰质炎病毒减毒活疫苗(Oral Poliovirus Vaccine, OPV)的行为三个方面分析可能影响轮状病毒减毒活疫苗的免疫反应的因素。本研究中,6-13周龄健康婴幼儿接种三剂Ⅲ价轮状病毒基因重配减毒活疫苗,每剂间隔1个月,分别在首剂接种前、第3剂接种后1个月采集血样,进行G2、G3、G4型特异性轮状病毒免疫球蛋白A (Rotavirus-Immunoglobulin A, RV-IgA)抗体测定。分别根据各型免后RV-IgA是否阳转,将接种人群分为各型血清阳转组和血清未阳转组。同时检测接种人群的免前血清G2、G3、G4型特异性轮状病毒中和抗体水平。统计各型中和抗体阳性率和抗体水平在两组间是否有差异。结果发现：接种人群中免前3个型特异性的轮状病毒中和抗体阳性率和抗体几何平均滴度分别为G4型最低(49.24%,12),G2型居中(82.95%,20),G3型最高(100%,91)。与此相对应地,群体免后呈现出RV-IgA的血清抗体水平G3型(76U/mL)最低,G2型(86U/mL)居中,G4型(90U/mL)最高的分布特点。免前各型特异性中和抗体的阳性率和抗体水平均为血清阳转组低于血清未阳转组,除G3型外,G2和G4型免前中和抗体的阳性率和抗体水平在两组之间均有统计学差异(P0.05)。提示母传抗体可能会抑制轮状病毒减毒活疫苗的免疫反应。根据接种者首次接种Ⅲ价轮状病毒基因重配减毒活疫苗时的年龄,将其分为两组,平均年龄分别为8周龄和12周龄,统计各型免前中和抗体和免后RV-IgA在两组间的差异,分析推迟免疫接种程序是否能够消除母传抗体的影响,增强疫苗免疫反应。与8周龄人群相比,在12周龄接种人群中,除G2型免前中和抗体阳性率略高(83.19%：82.76%),以及G3型阳性率均为100%外,免前其它型中和抗体阳性率和抗体水平均较低,G3型抗体水平差异有统计学意义(P=0.003)。对于免后RV-IgA,在12周龄组中,除G3型RV-IgA的几何平均滴度略低(76：77)外,其它型免后RV-IgA阳转率和抗体水平均较8周龄组高,但差异无统计学意义。提示母传抗体随着时间的推移逐渐衰减,但在我国将疫苗接种时间推迟至12周龄,实际上对消除母传抗体的影响有一定的帮助,但也需要更多年龄组的研究。在上述接种人群的基础上,将免后任何型RV-IgA阳转的接种者归为血清阳转组,所有型别RV-IgA均未阳转的归为血清未阳转组,分别从两组中随机选取55人和41人通过测序法进行HLA-A、-B、-C、-DRB1、-DQB1分型,计算HLA各位点等位基因型别、单体型和超型在两组人群中的分布频数,统计两组间等位基因、单体型和超型的分布是否有差异,分析HLA基因多态性与轮状病毒减毒活疫苗免疫反应的关系。结果发现HLA-B*40:01在血清未阳转组的分布频率明显高于血清阳转组,差异有统计学意义,与轮状病毒减毒活疫苗接种后无免疫应答相关。为了评价同时接种OPV的行为是否会影响轮状病毒减毒活疫苗的免疫反应和血清阳转率,本研究以葛兰素史克公司生产的Rotarix作为研究对象,将受试人群随机分为两组。一组按照常规两剂接种程序完成两剂口服Rotarix的接种,并根据国家规划接种年龄接种计划免疫的OPV,但与Rotarix不在同一天接种。另一组在按照常规接种程序完成两剂口服Rotarix的接种基础上,同时接种OPV。分别在首剂接种前、第2剂Rotarix接种后1个月采集血样,进行RV-IgA抗体测定。通过统计分析两组的RV-IgA血清阳转率和水平分布是否有统计学差异。结果显示间隔接种和同时接种组的血清RV-IgA阳转率分别为73.84%和63.95%,差异有统计学意义(P=0.033);两组的免后RV-IgA抗体几何平均数分别为97和90,差异无统计学意义(P0.05)。说明同时接种口服脊髓灰质炎减毒活疫苗可能会影响轮状病毒减毒活疫苗的血清阳转率,但尚未发现其对群体的抗体水平的影响。与同时接种组相比,间隔接种组免后1年血清RV-IgA阳转率和几何平均滴度均较高,差异有统计学意义(P0.05)。同时接种组在免后1年中的抗体阳转率和GMT下降更为明显,提示同时接种对RV-IgA抗体水平的维持也有影响。综上所述,本研究结果表明宿主母传抗体、宿主基因多态性和OPV都可能是影响轮状病毒减毒活疫苗免疫原性的因素,对轮状病毒疫苗的研发、临床试验的设计和免疫程序的制定有一定的参考价值。
[Abstract]:Rotavirus (RV) is one of the major pathogens causing severe diarrhoea in infants worldwide. Rotavirus infection is called "democratic disease". Both developed and developing children will be infected and bring serious social and economic burden to all countries in the world. But the mortality rate of children under 5 years old in developing countries is caused by developing countries. Higher. Vaccination is the only effective way to prevent rotavirus diarrhea and reduce mortality. In the past ten years, the human rotavirus vaccine (Rotarix) produced by the GlaxoSmithKline Co and the oral rotavirus five valence live vaccine (RotaTeq) produced by Mercedes are widely used worldwide. The results show that the rotavirus attenuated live vaccine has an effective protective effect in developed countries. However, the effectiveness and immunogenicity of the vaccine are not ideal in the developing countries which need them most. For this phenomenon, it is urgent to find the reasons to improve the effectiveness of the rotavirus vaccine in the developing country. A study was carried out to explain the reasons for the difference in immunogenicity from the nutritional status of the inoculant, the intestinal flora, the breastfeeding behavior and the prevalence of the virus strains. However, the comprehensive analysis was not able to give a comprehensive and systematic explanation, and a more in-depth study of the immune system was needed. The heterogeneous network structure leads to the difference in the immunogenicity and effectiveness of the rotavirus vaccine in different regions, which may not only be limited to the above factors. In view of this, the present study is based on the polymorphism of the prefree maternal antibody, Human Leukocyte Antigen, H LA gene and the simultaneous inoculation of oral poliomyelitis virus in the inoculant. Three aspects of the behavior of Oral Poliovirus Vaccine (OPV) were analyzed in this study. In this study, 6-13 weeks old healthy infants were inoculated with three doses of rotavirus gene redistribution attenuated live vaccine, each interval of 1 months, before the first inoculation and 1 after third doses of inoculation, respectively. Blood samples were collected for G2, G3, and G4 specific rotavirus immunoglobulin A (Rotavirus-Immunoglobulin A, RV-IgA) antibody determination in the month. The inoculated crowd was divided into different seropositive groups and serum unpositive rotation groups according to the positive changes of each type of RV-IgA, and the pre free serum G2, G3, G4 type rotavirus was detected in the inoculated population. The positive rate of neutralization antibody and antibody level were different between the two groups. The results showed that the positive rate of neutralization antibody and the geometric mean titer of the first 3 types of rotavirus were the lowest (49.24%, 12), G2 type (82.95%, 20), and the highest G3 type (100%, 91) in the inoculated population. The serum antibody level of RV-IgA (76U/mL) was the lowest, G2 type (86U/mL) was in the middle and the highest distribution of G4 type (90U/mL). The positive rate and antibody level of the specific neutralizing antibody were lower than that of the serum non positive group, and the positive rate and antibody of the G2 and G4 type pre neutralizing antibody and antibody, except G3 type, were all the lowest. The level was statistically different between the two groups (P0.05). It suggested that the maternal antibody may inhibit the immune response of the rotavirus attenuated live vaccine. According to the age of the inoculant, the age of the first inoculation of the rotavirus gene and the live attenuated vaccine, it was divided into two groups. The average age was divided into 8 weeks and 12 weeks of age. The difference between the two groups of the two groups and the postponement of the immunization program could eliminate the influence of the maternal antibody and enhance the immunization response. Compared with the 8 week old population, the positive rate of the G2 type preempting neutralization antibody was slightly higher (83.19%:82.76%), and the positive rate of the G3 type was all outside the other type in the 12 week old population. The positive rate of antibody and the level of antibody were low, and the difference of G3 type antibody level was statistically significant (P=0.003). For the post free RV-IgA, in the 12 week old group, except the geometric mean titer of G3 type RV-IgA was slightly lower (76:77), the other type of RV-IgA positive conversion rate and antibody level were higher than those of the 8 week old group, but the difference was not statistically significant. The time lapse gradually attenuated, but in our country the delay of vaccination to 12 weeks was actually helpful to eliminate the influence of maternal antibody, but it also needed more age groups. On the basis of the above inoculation population, any type of RV-IgA positive inoculant was classified as serological positive group, and all types of RV-IgA were not positive. HLA-A, -B, -C, -DRB1, -DQB1 typing were randomly selected from the two groups, and the distribution frequency of HLA, monotype and super type in the two groups was calculated, and the distribution of the two groups was statistically different between the two groups, and the analysis of the HLA base was analyzed. The relationship between polymorphism and the immune response of rotavirus attenuated live vaccine was found. The results showed that the distribution frequency of HLA-B*40:01 in the non positive seroconversion group was significantly higher than that in the serological positive group. The difference was statistically significant, and it was not related to the immune response after the rotavirus attenuated live vaccine. In order to evaluate the effect of the behavior of OPV at the same time, it could affect the rotaform disease. The immune response and serum positive rate of the live attenuated vaccine were studied in this study with the Rotarix produced by GlaxoSmithKline Co. The subjects were randomly divided into two groups. One group was inoculated with two doses of Rotarix in accordance with the routine two doses of inoculation, and OPV was immunized by the national plan for inoculation of age inoculation, but not with Rotarix. The other group was inoculated on the same day. The other group was inoculated on the basis of two doses of oral Rotarix according to the routine inoculation procedure. At the same time, the blood samples were collected by OPV. before the first inoculation and 1 months after the second doses of Rotarix. The serum positive rate and the level distribution of the two groups of RV-IgA were statistically analyzed. The RV-IgA positive rates of serum RV-IgA in the interval inoculation group and the simultaneous inoculation group were 73.84% and 63.95%, respectively, and the difference was statistically significant (P=0.033). The geometric mean of RV-IgA antibody in the two groups was 97 and 90, respectively, and the difference was not statistically significant (P0.05). The serum positive rate of the live vaccine was not found to affect the antibody level of the group. Compared with the same group, the serum RV-IgA positive rate and the geometric mean titer were higher in the interval 1 years after the vaccination group, and the difference was statistically significant (P0.05). At the same time, the positive rate of antibody and the decrease of GMT in the inoculated group were more obvious, suggesting that the antibody positive rate and the decrease of the antibody were more obvious. At the same time, inoculation also has an impact on the maintenance of RV-IgA antibody level. To sum up, the results of this study suggest that host maternal antibody, host gene polymorphism and OPV may be factors affecting the immunogenicity of the rotavirus attenuated live vaccine, and have a certain reference price for the development of rotavirus vaccine, the design of clinical trials and the formulation of immune procedures. Value.
【学位授予单位】：北京协和医学院
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R392

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