脂质体流感疫苗制备及体液免疫应答的研究

目的：制备脂质体流感疫苗并对其体液免疫效果和保护效率进行研究.方法：采用薄膜法与冷冻干燥法相结合的方法制得多层脂质体;用制得的脂质体流感疫苗和普通疫苗分别免疫小鼠,用血凝抑制实验（HI）和酶联免疫吸附试验（ELISA）对免后2～13周的小鼠血清的抗体水平进行检测,HI检测其特异性抗体,ELISA检测IgG抗体水平并对小鼠的保护效率进行检测.结果：实验中,脂质体流感疫苗在2μg/mouse组和4μg/mouse两个剂量组中,不同免疫时间内其HI值可分别较非脂质体疫苗组高出2～3和4倍,产生抗体的水平经ELISA实验得出较非脂质体疫苗组高出1倍左右,故可激发更高的体液免疫;保护效力为4/6.结论：脂质体流感疫苗能够刺激机体产生更高的体液免疫和更高的保护效力.     

Immunization with Recombinantly Expressed LRP4 Induces Experimental Autoimmune Myasthenia Gravis in C57BL/6 Mice

Background: Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction (NMJ), characterized with muscle weakness. While MG develops due to acetylcholine receptor (AChR) antibodies in most patients, antibodies to muscle-specific receptor tyrosine kinase (MuSK) or low-density lipoprotein receptor-related protein 4 (LRP4) may also be identified. Experimental autoimmune myasthenia gravis (EAMG) has been previously induced by both LRP4 immunization and passive transfer of LRP4 antibodies.

Objective: Our aim was to confirm previous results and to test the pathogenic effects of LRP4 immunization in a commonly used mouse strain C57BL/6 (B6) using a recombinantly expressed human LRP4 protein.

Methods: B6 mice were immunized with human LRP4 in CFA, Torpedo Californica AChR in CFA or only CFA. Clinical and pathogenic aspects of EAMG were compared among groups.

Results: LRP4- and AChR-immunized mice showed comparable EAMG clinical severity. LRP4-immunized mice displayed serum antibodies to LRP4 and NMJ IgG and complement factor C3 deposits. IgG2 was the dominant anti-LRP4 isotype. Cultured lymph node cells of LRP4- and AChR-immunized mice gave identical pro-inflammatory cytokine (IL-6, IFN-γ and IL-17) responses to LRP4 and AChR stimulation, respectively.

Conclusion: Our results confirm the EAMG-inducing action of LRP4 immunization and identify B6 as a LRP4-EAMG-susceptible mouse strain. Demonstration of complement fixing anti-LRP4 antibodies in sera and complement/IgG deposits at the NMJ of LRP4-immunized mice indicates complement activation as a putative pathogenic mechanism. We have thus developed a practical LRP4-induced EAMG model using a non-conformational protein and a widely available mouse strain for future investigation of LRP4-related MG.     

含有丙型肝炎病毒核心基因表达质粒的构建及其基因免疫

目的：研究丙型肝炎病毒（ＨＣＶ）核心（Ｃ）基因免疫诱生特异性免疫应答的可行性。方法：将ＨＣＶ Ｃ基因片段插入真核表达载体ｐｃＤＮＡ３质粒ＣＭＶ启动子的下游,构建真核表达载体ｐｃＤＮＡＨＣＶ－Ｃ,分别转染小鼠骨髓瘤细胞ＳＰ２／０和人肝癌细胞７７２１进行瞬时表达,用免疫荧光法和Ｗｅｓｔｅｒｎ－ｂｌｏｔ检测表达产物,将重组质粒注射,ＢＡＬＢ／ｃ（Ｈ－２＾ｄ）小鼠股四头肌,ＥＬＩＳＡ法检测血清中抗体产生水     

永州市零陵区2005--2007年儿童计划免疫接种率调查

目的初步了解永州市零陵区儿童计划免疫现状,评价2005～2007年报告接种率情况,为加强计划免疫工作,有效提高接种质量提供依据。方法采取分层随机抽样的方法抽查6个街道及2个农贸市场,按《全国常规免疫接种率监测方案》的方法进行接种率进行评价,连续抽查3年。结果全区2005～2007年卡介苗（BCO）、脊髓灰员炎疫苗（OPV）、百白破（DPT）、麻疹疫苗（MV）全程接种率在2005、2006、2007年调查中分别为83.7％、93.6％、95.5％;备单苗接种率由2005年的不足84％提高到2005年的96％;乙肝疫苗（HBV）三年的接种率分别为82.4％、88．6％、86.5％;建卡率、建证率和卡疤率也提高到96％以上。结论本地区儿童计划免疫仍保持着工怍的连续性并将儿童接种率维持在一定水平,各指标逐年提高,到2007年都达到了或接近了90％,但还存在不足．     

葫芦岛市2007年常规免疫接种报告及分析

目的采用常规免疫接种报告、小样本抽样调查、用建卡率估算实际接种率、以计算R比值、D差值评价常规报表中的数据进行综合评估由于社会经济的发展。方法通过计算接种率的R比值、D差值,利用逻辑对比关系,推算报告接种率的真实性、可靠性。结果我市报告接种率虽然很高,但资料质量较差,大部分地区存在逻辑性错误。估计接种率低于报告接种率,我市2007年四种疫苗的实际接种率大约在90%左右。结论通过对常规免疫接种率报告的分析,有助于发现免疫接种中存在的问题,提高报表质量,使之得到纠正。     

两种不同剂型人用狂犬疫苗不良反应与免疫效果评价

目的:评价辽宁成大人用狂犬疫苗(水剂)和辽宁依生人用狂犬疫苗(冻干剂)的不良反应及免疫效果,为人用狂犬疫苗免疫接种提供参考依据。方法:采取随机抽样方法,选取狂犬病暴露后到预防医学门诊注射人用狂犬疫苗人群为对象。将入选对象随机分为A、B两组,分别接种辽宁成大人用狂犬疫苗(水剂)和辽宁依生人用狂犬疫苗(冻干剂),采用随机双盲方法观察接种疫苗后72 h不良反应发生率。使用宁波天润生物有限公司生产的人狂犬病毒IgG抗体测定试剂,采用间接ELISA法,检测人用狂犬疫苗注射后人血清中狂犬病毒IgG抗体。结果:不良反应发生率A组24.03%,B组8.82%,两组不良反应发生率的差异有统计学意义(χ2=8.65 P<0.01);抗体阳转率A组97.5%、B组97.6%,抗体阳转率差异无统计学差异(χ2=0.46 P>0.05)。结论:辽宁成大人用狂犬疫苗(水剂)和辽宁依生人用狂犬疫苗(冻干剂)相比较,辽宁依生人用狂犬疫苗(冻干剂)的不良反应率相对较小,为首选。     

珠池医院2010～2012年疑似预防接种异常反应分析

目的 分析珠池医院2010～2012年疑似预防接种反应(AEFI)发生特征,了解预防接种安全性,为提高预防接种质量提供依据. 方法 采用描述性流行病学方法对收集的AEFI数据进行分析. 结果 珠池医院2010～2012年共报告AEFI为273例,发生率为70.47/10万,3年分别为132例(110.20/10万),67例(55.24/10万),74例(50.58/10万),一般反应有246例占90.11％,偶合反应24例,占8.79％,异常反应3例,占1.10％,无疫苗质量事故、接种事故;一类疫苗发生AEFI为205例,发生率为71.52/10万,以百白破、白破二联、含麻疹类疫苗、A群流脑疫苗、乙脑疫苗为主,二类疫苗发生AEFI为68例,发生率为67.51/10万,以甲型流感(裂解)疫苗、流感疫苗、口服轮状病毒疫苗、水痘疫苗、狂犬疫苗、23价肺炎疫苗为主.2010年、2011年一类疫苗之间、二类疫苗之间AEFI发生率差别均有显著性. 结论 认真做好接种前告知、接种规范培训、接种后观察工作,同时开展AEFI诊断、处理、调查培训,可以有效减少AEFI和接种事故的发生,同时能提高AEFI监测的准确性.     

白藜芦醇对小鼠氧惊厥的保护作用及其可能机制

目的:以真核质粒pcDN3.1( )为载体携带丙肝病毒高变区1(HVR1)相关模拟表位DNA序列对小鼠进行基因免疫,观察其诱导细胞免疫反应的效果.方法:根据HCV HVR1模拟表位多肽序列,合成DNA序列,并将其连接到pcDN3.1( )上,构建为pcDN3.1-SP.免疫中分别采用2种剂量pcDN3.1-SP(10μg和100 μg),以及10μg质粒中混合了非甲基化CpG基序(-CpG),以其作为佐剂增强免疫原性,并比较其与100μg剂量的免疫效果.杀鼠、收集血清、分离脾细胞;ELISA法检测小鼠体液中的抗体;脾细胞经混合肽刺激后,用流式细胞仪检测CD8 IFN-γ 细胞;用非放射性MTS法检测细胞增殖反应;以非放射性LDH法检测CTL反应.结果:混合肽体外刺激100μg和10μg-CpG基因免疫小鼠脾淋巴细胞后,T细胞增殖反应明显;脾淋巴细胞中CD8 IFN-γ 细胞增多;并能检测到明显的CTL反应,同时伴有较弱体液免疫反应.结论:合成的模拟表位中可能含有T细胞和B细胞表位;非甲基化CpG基序增强了DNA免疫效果.     

新疫苗纳入国家免疫规划的评价维度及指标分析

目的 对新疫苗纳入国家免疫规划涉及的决策要素相关的文献进行系统梳理。方法 通过8个中英文文献数据库检索国内外相关文献,归纳各国进行免疫决策时的评价维度及核心指标等。结果 纳入41篇文献,内容以案例研究为主,实证研究较少。各文献基本遵循疾病、疫苗、卫生系统的评价框架,但有不同程度的延伸。疾病死亡率、疫苗安全性及有效性、成本效果评价等为高频评价指标。本研究梳理出基于“疾病-疫苗-能力-效益评价”的4维度13个要素43个指标的评价体系。结论 国内外关于疫苗决策的研究处于发展阶段,我国应增强疫苗纳入免疫规划的评价框架的可操作性及广度,注重本土的流行病学、卫生经济学数据收集,进一步发挥国家免疫规划技术工作组在疫苗循证决策中的作用。     

Impact of the COVID-19 pandemic on routine immunization coverage in children under 2 years old in Ontario,Canada: A retrospective cohort study

BackgroundThe COVID-19 pandemic has caused a disruption in childhood immunization coverage around the world. This study aimed to determine the change in immunization coverage for children under 2 years old in Ontario, Canada, comparing time periods pre-pandemic to during the first year of the pandemic.MethodsObservational retrospective open cohort study, using primary care electronic medical record data from the University of Toronto Practice-Based Research Network (UTOPIAN) database, from January 2019 to December 2020. Children under 2 years old who had at least 2 visits recorded in UTOPIAN were included. We measured up-to-date (UTD) immunization coverage rates, overall and by type of vaccine (DTaP-IPV-Hib, PCV13, Rota, Men-C-C, MMR, Var), and on-time immunization coverage rates by age milestone (2, 4, 6, 12, 15, 18 months). We compared average coverage rates over 3 periods of time: January 2019-March 2020 (T1); March-July 2020 (T2); and August-December 2020 (T3).Results12,313 children were included. Overall UTD coverage for all children was 71.0% in T1, dropped by 5.7% (95% CI: ?6.2, ?5.1) in T2, slightly increased in T3 but remained lower than in T1. MMR vaccine UTD coverage slightly decreased in T2 and T3 by approximately 2%. The largest decreases were seen at ages 15-month and 18-month old, with drops in on-time coverage of 14.7% (95% CI: ?18.7, ?10.6) and 16.4% (95% CI: ?20.0, ?12.8) respectively during T2. When stratified by sociodemographic characteristics, no specific subgroup of children was found to have been differentially impacted by the pandemic.ConclusionChildhood immunization coverage rates for children under 2 years in Ontario decreased significantly during the early period of the COVID-19 pandemic and only partially recovered during the rest of 2020. Public health and educational interventions for providers and parents are needed to ensure adequate catch-up of delayed/missed immunizations to prevent potential outbreaks of vaccine-preventable diseases.