2～59岁健康人群接种ACYW135群脑膜炎球菌多糖疫苗的免疫原性观察

目的评价ACYW135群脑膜炎球菌多糖疫苗在2～59岁健康人群中的免疫原性。方法 2～59岁健康人群接种者随机抽样(n=60),接种一剂四价脑膜炎球菌多糖疫苗。采集接种前和接种后1个月血清,采用体外杀菌试验(Serum bactericidal assay,SBA)检测血清中抗A、C、Y、W135群脑膜炎球菌的血清杀菌滴度。结果免疫前、后血清抗A群脑膜炎球菌的血清杀菌滴度GMTs(95%CI)分别为1241(736,2091)和7559(5520,10351)(P<0.05);抗C群脑膜炎球菌的血清杀菌滴度GMTs(95%CI)分别为4(9,21)和4787(2947,7775)(P<0.05);抗W135群脑膜炎球菌的血清杀菌滴度GMTs(95%CI)分别为16(9,28)和368(162,883)(P<0.05);抗Y群脑膜炎球菌的血清杀菌滴度GMTs(95%CI)分别为120(58,246)和1373(687,2745)(P<0.05)。免疫前和免疫后血清抗A群脑膜炎球菌的杀菌滴度≥128的比例分别为87(77.4,95.1)%和100(83.2,100)%;抗C群脑膜炎球菌的比例分别为17(8.3,28.5)%和97(88.5,99.6)%;抗W135群脑膜炎球菌的比例分别为13(5.9,24.6)%和68(55.0,79.7)%;抗Y群脑膜炎球菌的比例分别为57(43.2,69.4)%和85(73.4,92.9)%。免疫后较免疫前抗A群、C群、W135群和Y群脑膜炎球菌杀菌抗体滴度≥4倍升高的比例分别为50(27.2,72.8)%、97(88.5,99.6)%、62(43.2,73.9)%和55(41.6,67.9)%。结论虽然免疫前人群由于地方和国家免疫计划的实施已具有较高水平的抗A群脑膜炎球菌的血清杀菌滴度,但接种ACYW135群脑膜炎球菌多糖疫苗后可以使其保护水平进一步提高,并使人群对C群、W135群和Y群脑膜炎球菌的低水平杀菌抗体滴度均显著升高达到保护水平,证明ACYW135群脑膜炎球菌多糖疫苗在2～59岁健康人群中具有比较好的免疫原性。     

河南省健康儿童A、C、Y和W135群流行性脑脊髓膜炎抗体水平回顾性调查

目的观察从未接种脑膜炎奈瑟菌疫苗的健康儿童人群抗体水平。方法采用血清体外杀菌试验检测来自2013年河南省3月龄~6岁儿童的1 944份血样中抗A、C、Y和W135群流行性脑脊髓膜炎(简称流脑)抗体水平,计算抗体几何平均滴度(GMT)和易感人群比例,并进行统计分析。结果研究结果显示,受试者A、C、Y和W135群流脑血清抗体GMT为1∶0.66~1∶1.74,易感人群比例为91.82%~97.63%;不同性别人群血清抗体GMT和易感人群比例差异均无统计学意义(P0.05)。进一步分析发现,不同年龄组受试者A、C和W135群流脑杀菌抗体GMT和抗体滴度≥1∶8人群比例均无统计学意义(P0.05)。在6~23月龄受试者中Y群流脑杀菌抗体GMT(1∶3.42)和抗体滴度≥1∶8人群比例(17.51%)显著高于3~5月龄和2~6岁两个年龄组,差异有统计学意义(P0.05)。结论 3月龄~6岁儿童A、C、Y和W135群流脑抗体水平均较低,为减轻儿童免疫负担,建议对这类易感人群接种多价流脑结合疫苗。     

检测四价脑膜炎球菌多糖疫苗中A群多糖含量ELISA法的建立

目的建立双抗体夹心ELISA法,对A群流脑多糖抗原进行特异性定量测定。方法制备抗A群多糖的特异性多克隆抗体,所得抗血清经辛酸-硫酸铵沉淀法纯化后,用过碘酸钠法制备辣根过氧化物酶标记多克隆抗体。分别以抗A群多糖多克隆抗体作为包被抗体及酶标二抗,建立双抗体夹心ELISA法,优化反应条件,对A群多糖抗原进行特异性定量测定。结果一系列验证试验表明,该法特异性较好,未检出与C、Y、W135群多糖的交叉反应;1.25～20 ng/mL多糖浓度范围的剂量反应曲线线性最佳,相关系数大于0.98,经实验内10次及不同试验间以16、84、ng/mL测定3次A群多糖中的含量,变异系数在6.3%～11.5%间,回收率在91.8%～105.9%之间,符合常规质控要求,检测限量为4 ng/mL。采用该法测定3批ACYW135群四价脑膜炎球菌多糖疫苗中A群多糖含量、分子大小及回收率的结果均符合规程草案质量标准。结论建立的双抗体夹心ELISA法可尝试用于ACYW135群脑膜炎球菌多糖疫苗中A群多糖的关键质量指标的检测。     

冻干A+C群脑膜炎球菌多糖疫苗安全性和免疫原性观察

为了评价冻干A+C群脑膜炎球菌多糖疫苗(MPV)的安全性和免疫原性,按随机、盲法的原则,评价疫苗免疫后不良反应发生率、抗体阳转率及抗体几何平均滴度(GMT)。将606名健康观察者分为2～5岁、6～12岁、13～17岁、18～60岁四个年龄组,结果显示,该疫苗全身反应发生率2.64%,局部反应发生率1.32%,四个年龄组疫苗免疫后杀菌抗体阳性率分别为100%、100%、99.3%和100%,免疫后A群杀菌抗体GMT分别为1:250.47、1:190.61、1:144.22和1:205.79,免疫后C群杀菌抗体GMT分别为1:273.33、1:551.18、1:788.26和1:809.81,冻干A+C群多糖疫苗在≥2岁人群中具有良好的安全性和免疫原性,建议推广使用A+C群MPV。     

A＋C群脑膜炎球菌多糖疫苗的制备及其接种人体后的血清学效果

在现行的A群脑膜料球菌多糖原液制造工艺的基础上,经部分改进后进行C群脑膜炎球菌多糖原液的生产。3批中试A＋C群脑膜炎球菌多糖疫苗经全面检定后,各项指标均符合WHO《生物制品规程》的要求。该疫苗在接种人体后,5－13岁儿童组,抗A群及抗C群脑膜炎球菌的血清杀菌抗体4倍增长率为96．59％和92．15％;≤2岁儿童组,抗A群及抗C群脑膜炎球菌的血清杀菌抗体4倍增长率为68．60％和69．77％。2组儿童接种后1个月的抗A群及抗C群膜炎球菌血清杀菌抗体几何平均滴度（GMT）与接种前均有显著性差异（P＜0．001）。     

火箭免疫电泳法检测ACYW135群脑膜炎球菌多糖疫苗多糖含量和分子大小的初步验证

目的对火箭电泳法用于检测ACYW135群脑膜炎球菌多糖疫苗的多糖含量和多糖分子大小进行验证。方法用化学法和火箭电泳法分别检测ACYW135群脑膜炎球菌多糖疫苗的多糖含量和多糖分子大小,统计学分析两种方法的检测结果。结果两种方法的检测结果差异无统计学意义。结论火箭电泳法可以用于检测ACYW135群脑膜炎球菌多糖疫苗的多糖含量和多糖分子大小。     

脑膜炎球菌荚膜多糖氧乙酰基相关特性及其作用机理

氧乙酰基(O-acetyl,OAc)存在于许多细菌多糖中,如脑膜炎球菌(meningococcus)A、C、W135、Y群荚膜多糖、大肠杆菌K1型荚膜多糖等均存在氧乙酰化修饰。由于荚膜多糖(capsular polysaccharides, CPS)中OAc的分布和占比被视为脑膜炎球菌多糖候选疫苗的关键质量控制因素,氧乙酰化修饰对多糖疫苗的免疫原性的重要作用,特别是脑膜炎球菌CPS OAc对其疫苗免疫原性的影响越来越受到关注。现就脑膜炎球菌CPS OAc的相关特性和检测方法、迁移因素、OAc修饰及其作用、OAc转移酶的作用机制、OAc对脑膜炎球菌免疫原性的影响作一概述,有助于脑膜炎球菌荚膜多糖疫苗安全性和免疫原性的评价。     

比色法与核磁共振法测定A、C、Y、W135群脑膜炎球菌荚膜多糖氧乙酰基含量的比较

目的比较Hestrin比色法(简称比色法)和核磁共振(nuclear magnetic resonance,NMR)法在检测A、C、Y、W135群脑膜炎球菌荚膜多糖氧乙酰基(O-Acetyl,OAc)含量的相关性和精密度。方法用比色法和NMR法测定A、C、Y、W135群脑膜炎球菌荚膜多糖及其多糖衍生物,Y、W135群荚膜多糖水解物的OAc含量,比较分析两种方法的相关性及精密度。结果两种方法检测A、C、Y、W135群脑膜炎球菌荚膜多糖OAc含量的决定系数分别为R~2≥0.954、R~2≥0.960、R~2≥0.969、R~2≥0.972;比色法检测3批C群脑膜炎球菌荚膜多糖(PSC)OAc含量的精密度,SD值分别为0.21、0.21、0.18,对应CV值分别为9.03%、9.01%、8.70%(95%置信区间);NMR法检测3批A群脑膜炎球菌荚膜多糖(PSA)OAc含量的精密度,SD值分别为0.66、0.78、0.83,对应CV值分别为0.72%、0.85%、0.93%(95%置信区间);结论比色法和NMR法在检测A、C、Y、W135群脑膜炎球菌荚膜多糖OAc含量方面相关性良好,精密度良好,核磁法较比色法精密度更高。     

离子色谱法测定ACYW135群脑膜炎球菌结合物中Y群及W135群多糖含量

目的利用离子色谱法即高效阴离子交换柱层析—脉冲安培检测法(HPAEC-PAD),测定ACYW135脑膜炎球菌多糖蛋白结合物中Y群和W135群多糖含量的方法,并加以验证。方法将ACYW135脑膜炎球菌多糖蛋白结合物中Y群和W135群多糖用三氟乙酸(TFA)水解为特异性单糖(葡萄糖、半乳糖),并去除水解液中残留的TFA,用HPAEC-PAD分析检测,用PA10糖分析柱分离单糖,电化学检测器测定葡萄糖及半乳糖含量,用Chromeleon色谱工作站记录并分析数据。对上述方法进行专属性、准确性、重复性验证,确定该方法的检出限和定量限。结果 Y群和W135群多糖在TFA2.5 mol/L(终浓度)、90℃、4 h可完全水解为葡萄糖、半乳糖。对照品葡萄糖及半乳糖在0.10~60.00μg/m L范围内,质量浓度和色谱峰面积呈较好的线性关系,r均大于0.99,回收率为87.94%~109.80%,相对标准偏差(RSD)为1.00%~2.00%,检出限为0.05μg/m L(信噪比3∶1),定量限为0.10μg/m L(信噪比10∶1)。结论离子色谱法可同时检测脑膜炎球菌多糖蛋白结合物中Y群和W135群糖含量,该方法操作简便、灵敏、快速,干扰小,重现性好,适用于对相关疫苗生产过程中的质量控制。     

速率比浊法检测ACYW135群脑膜炎球菌结合疫苗中各群多糖含量

目的建立速率比浊法准确检测ACYW135群脑膜炎球菌结合疫苗(group ACYW135 meningococcal conjugate vaccine)的各群多糖含量。方法制备多糖参考品和抗血清,建立检测ACYW135群脑膜炎球菌结合疫苗各群多糖含量的速率比浊法,对建立的方法进行验证及初步应用。结果①建立的方法具备高度的特异性,各群血清仅与本群多糖抗原发生特异性反应,与非本群多糖抗原无交叉反应;②在质量浓度为0.5～5.0μg/mL多糖参考品检测区间线性良好,相关系数r>0.98;③各群血清的最低检测限均低于质量浓度为0.35μg/mL;④批内和批间变异系数(CV)值分别为0.83%～5.34%和2.33%～13.88%,加样回收率为90.5%～118.4%,精密度和准确度均符合常规质量控制要求;⑤初步应用结果显示,建立的方法可准确检测疫苗的各群多糖含量,且与火箭电泳法检测结果差异无统计学意义(P>0.05)。结论建立的方法简便快捷、灵敏准确、自动化程度高,可有效检测ACYW135群脑膜炎球菌结合疫苗的各群多糖含量。     

Nucleotide sequence analysis of the sialyltransferase genes of meningococcal serogroups B,C, Y and W135

A rapid method for serogrouping meningococci is essential for the characterization of phenotypically non-groupable meningococcal isolates and clinical samples, particularly for public health management purposes. The Scottish Meningococcus and Pneumococcus Reference Laboratory (SMPRL) provides serogrouping results of meningococcal isolates and clinical samples using a PCR assay which detects restriction fragment length polymorphisms in meningococcal serogroups B, C, Y and W135. Although this PCR system was invaluable when first introduced, it has several drawbacks and lacks the required sensitivity for detecting DNA in clinical samples. Due to the recent introduction of the meningococcal group C conjugate vaccine and an impending group B vaccine, a more robust and informative method for serogroup determination is required. A protocol was devised allowing PCR amplification of the siaD gene of serogroup B, C, Y and W135 meningococci. This system was multiplexed and allowed serogroup differentiation between serogroups B and C and also between B/C and Y/W135 by product size analysis. A nested stage was incorporated into the system for enhanced detection of meningococci in clinical samples, and finally a sequencing protocol was designed allowing detection of any nucleotide changes within the siaD gene. This system allows rapid serogrouping results for use within an agarose gel system as well as more informative results when used for sequencing within the siaD gene.     

The quantitative immunochemical determination of pneumococcal and meningococcal capsular polysaccharides by light scattering rate nephelometry

A quantitative nephelometric method was used for the measurement of the individual pneumococcal, as well as meningococcal, polysaccharides in the polyvalent vaccine final containers. This method is simple, rapid, inexpensive, and provides both qualitative and quantitative analyses of the polyvalent polysaccharide vaccines. By this method the individual pneumococcal types, 1, 2, 3, 4, 6A, 7F, 8, 9N, 12F, 14, 18C, 19F, 23F and 25 polysaccharides, were found to be present at 90-114% of the manufacturer's indicated concentrations; meningococcal group A, C, Y and W135 polysaccharides were at 90-108% of the manufacturer's listed concentrations. This nephelometric method coupled with gel filtration can also be used for measurement of the molecular sizes or stability of individual polysaccharides in the final container. Pneumococcal polysaccharide types 3, 6A, 9N and 19F, used as representative types, were treated with 0.5 N hydrochloric acid. The molecular sizes for types 3 and 9 N polysaccharides were stable to acid treatment. In contrast, types 6A and 19F polysaccharides were degraded. Heating meningococcal groups A, C, Y and W135 polysaccharides at 37 degrees C for 48 h did not affect their molecular size in the polyvalent vaccine.     

O-Acetylation status of the capsular polysaccharides of serogroup Y and W135 meningococci isolated in the UK

At a time when tetravalent conjugate vaccines for meningococcal serogroups A/C/Y/W135 are being formulated the O-acetylation status of their respective capsular polysaccharides has not previously been studied in the UK for all components. Although this has been elucidated for serogroup C, little is known about the O-acetylation status of serogroups W135 and Y. Meningococcal serogroup W135 (n=181) and Y (n=90) isolates submitted to the PHLS Meningococcal Reference Unit in 1996, 2000 and 2001 were investigated for O-acetylation capsular status by dot blot assay. Eight per cent of W135 and 79% of Y isolates respectively were found to be O-acetylated with a similar distribution found in both carrier and case isolates. An increase in O-acetylated W135 isolates was noted between 2000 (0%) and 2001 (21%) which was not due to the introduction of the Hajj associated W135 (ET 37 complex; serosubtype P1.5,2) isolates, all of which were de-O-acetylated. Although the biological relevance of O-acetylation status is unknown for these serogroups, an understanding of O-acetylation status of the respective polysaccharides may provide useful insights into the optimal vaccine formulation.     

W135群脑膜炎球菌发酵工艺的研究

为研究A、C、Y、W 135群流脑多糖疫苗,针对W 135群脑膜炎球菌的生长特性,采用国产50L发酵罐,针对流脑半综合液体培养基中葡萄糖浓度;培养温度、菌种接种浓度、pH、通氧量及搅拌速度等因素对W 135群脑膜炎球菌生长的影响,选择最适的培养条件。结果表明,选择半综合培养基中补加1%的葡萄糖培养效果良好,菌种接种浓度直接影响多糖复合物产量;最适pH值6.5~7.5的范围可维持W 135群链球菌快速生长;温度控制在36.5±0.2℃可得到较高的培养产物;培养过程中加大通气量及搅拌速度对培养结果有明显改善。确立了W 135群脑膜炎球菌的最适培养条件,在确定培养条件后连续进行3批500L罐放大中试培养,达到规模化生产要求。     

Improved antiserum agar method for the serogroup differentiation of Neisseria meningitidis Y and W135

Rabbit antisera prepared to meningococcal serogroups Y and W135 strains were compared with horse antisera using the antiserum agar method (ASA) for the serogroup identification of Neisseria meningitidis. Thirty-seven group Y strains formed immunoprecipitates with the Y rabbit serum only, whereas the same Y strains formed immunoprecipitates with both the Y and W135 horse antisera. Forty-seven W135 strains formed specific immunoprecipitates with both the rabbit and horse W135 antisera by ASA. None of the 166 meningococcal isolates, representative of other meningococcal serogroups, formed immunoprecipitates with the groups Y and W135 rabbit or horse antisera. Use of specific Y and W135 rabbit antisera in ASA provides an improved technique for the serogroup differentiation of groups Y and W135 meningococci.     

Vaccination against meningococcal disease in Europe: review and recommendations for the use of conjugate vaccines

At the end of 2005, six European countries had implemented public immunization campaigns with serogroup C conjugate vaccines, and all had experienced substantial declines in the incidence of serogroup C disease. A quadrivalent ACWY meningococcal vaccine is in use in the USA, but serogroup A is extremely rare in Europe and serogroups Y and W135 are infrequent causes of disease. This paper outlines recommendations on the use of conjugate vaccines in Europe based on the experience with meningococcal C conjugate (MCC) vaccines so far.     

Meningococcal polysaccharide vaccines: A review

Polysaccharides produced by Neisseria meningitidis are pharmaceutically important molecules, and are the active components of vaccines against N. meningitidis serogroups A, C, W135 and Y. Effective vaccines based on capsular polysaccharide, polysaccharide conjugates and outer membrane vesicles have been developed for strains expressing capsular polysaccharides that define the sero groups A, C, Y and W135. However, conventional approaches to develop a vaccine for group B strains have been largely unsuccessful. This review focuses on the various aspects of fermentative production of meningococcal polysaccharide from N. meningitidis, methods of conjugation for improving the immunogenicity of polysaccharide vaccine, and efficient and cost effective methods for the purification of N. meningitidis capsular polysaccharide and outer membrane vesicles. In addition, different analytical techniques for the quantitative determination of polysaccharide vaccine and evaluation of structural integrity of conjugate vaccine have been described.