2017年深圳地区A/H3N2亚型流感病毒HA和NA基因的分子进化特征

  目的  了解深圳市2017年上半年流行的甲型H3N2亚型流感病毒HA和NA基因的分子进化特征,为预测流感病毒流行和变异提供科学依据。  方法  利用DNAStar、MEGA 7.0等生物信息学软件对研究分离的40株H3N2流感病毒的HA和NA基因及其编码的氨基酸序列进行比对,构建分子进化树,分析基因特征和变异情况。  结果  深圳分离株的同源性均达到97.8%~100.0%,位于亚洲北美人源分支。与世界卫生组织（World Health Organization,WHO）推荐的疫苗株A/Switzerland/9715293/2013（H3N2）和A/Hong Kong/4801/2014（H3N2）相比,有较高的序列相似性;与当年疫苗株对比发现,HA发生6个抗原位点和2个受体结合位点的改变,NA出现第151位酶活性位点的改变;HA和NA的潜在N-糖基化位点在数量和位置上也发生变化。  结论  深圳市2017年上半年甲型H3N2亚型流感病毒在流行过程中尚未发生明显变异,目前推荐的疫苗株仍对深圳地区人群有一定保护作用,HA和NA多个氨基酸位点的变异提示仍需加强H3N2亚型流感病毒分子水平的动态监测。     

国产流感裂解疫苗接种人体后安全性和免疫原性评价

目的:评价变更后流感毒株生产的国产流感裂解疫苗安全性和免疫原性。方法:对宁波市宁海县559例分组接种流感裂解疫苗者进行临床指标(局部反应、全身反应)的监测,并抽取其中213例,用流感病毒HI抗体测定法对接种者免疫前后的抗体滴度进行测定,比较免疫前后抗体阳转率及几何平均滴度(GMT)。结果:观察对象接种疫苗后发热反应发生率为1.22%,全身其他反应发生率为1.22%,局部反应发生率为1.07%,且以轻度反应为主。H1N1型、H3N2型、B型免后抗体阳转率分别为84.04%、85.45%、83.57%;不同年龄组免后抗体滴度的增长倍数,H1N1型在5.50～16.00倍之间,H3N2型在13.16～39.33倍之间,B型在7.28～24.85倍之间,各年龄组各抗体型别免疫前后GMT差别均有统计学意义。结论:国产流感裂解疫苗具有良好的安全性和免疫原性。     

2007-2009年郴州市H3N2亚型流感病毒HA1基因特性研究

目的了解2007-2009年郴州市H3N2亚型流感病毒流行情况及血凝素基因变异特征。方法 按时间先后顺序随机选择2007-2009年流感病原学监测中分离到的H3N2亚型毒株8株,提取病毒核糖核酸（RNA）,采用RT-PCR法扩增病毒HA1基因,纯化产物进行核苷酸序列测定并推导其氨基酸序列进行基因特性分析。结果H3N2亚型流感病毒在2007年为优势株,2008-2009年相对H1N1亚型流感病毒为弱势株;2007年分离株与该年疫苗株（A/Wisconsin/67/2005）比较,变异位点主要为G50E、S138A、K140I、R142G、N144D和L157S,抗原性发生了漂移;2008年分离株与2008-2009年疫苗株（A/Brisbane/10/2007）比较,变异位点主要为R142G、L157S;2009年分离株与该年疫苗株比较,变异位点主要为L157S、K173Q,2008-2009年分离株与该年疫苗株比较未发生明显变异。结论郴州市2007年H3N2亚型流感病毒HA1发生了明显变异,H3N2流感病毒较活跃,当年生产的疫苗预防效果较差;2008-2009年H3N2亚型流感病毒HA1与该年度疫苗株相比未发生明显变异,人群对其建立较好的免疫屏障,这是郴州市2008-2009年H3N2亚型流感病毒活动水平较低的主要原因。     

两种流行性感冒病毒裂解疫苗安全性与免疫原性研究

目的：评价国产流行性感冒裂解疫苗的安全性和免疫原性。方法：按整群随机抽样原则,以进口同类疫苗作为对照开展现场临床试验;比较两种疫苗免后不良反应率、抗体阳转率、保护率及几何平均滴度（GMT）。结果：试验组及对照组接种后全身不良反应率分别为2．7％和3．6％（P〉0．05）,局部不良反应率分别为7．2％和9．6％（P〉O．05）;试验疫苗流感病毒HINI、H3N2及B（亚）型的HI抗体总阳转率分别为81．6％,92．4％和78．0％;对照疫苗流感病毒HIN1、H3N2及B（亚）型的HI抗体总阳转率分别为87．1％,88．3％0和80．8％,三（亚）型流感抗体总阳转率差异无统计学意义;三（亚）型流感HI抗体达到保护水平的保护率的比较中,只有婴幼儿试验组和对照组的免后B型HI抗体滴度≥1：40,差异有统计学意义,试验组大于对照组,其余3组差异无统计学意义;三（亚）型流感抗体免后GMT的差异亦无统计学意义。结论：国产流感裂解疫苗全身和局部不良反应与进口同类疫苗无差异,免后抗体阳转率较高,抗体滴度上升幅度较大,具有良好的安全性和免疫原性。     

国产流行性感冒病毒裂解疫苗的安全性和免疫原性研究

目的评价国产流行性感冒（流感）病毒裂解疫苗的安全性和免疫原性。方法在江苏省盐城市建湖县选择332名观察对象,按随机、开放式的方法,开展现场观察试验。结果观察对象接种1针后局部反应率仅为0.6%,有15人次（4.5%）发生发热反应,且以轻度发热为主。血清学检测结果表明,接种疫苗后,流感病毒H1N1、H3N2、B（亚）型的HI抗体阳性率分别为95.0%、87.1%和88.1%,H1N1、H3N2、B（亚）型的HI抗体GMT增长倍数分别为33.28倍、7.76倍和26.04倍,抗体保护率分别为100.0%、99.7%、98.4%,3个型别之间阳性率、GMT增长倍数、保护率差异有统计学意义。结论国产流感病毒裂解疫苗临床安全性较好;免疫后抗体阳转率较高,抗体滴度上升幅度较大,具有良好的免疫原性,适于推广应用。     

2019—2020流感监测年度山东省B-Victoria系流感病毒基因特征

  目的  了解2019—2020流感监测年度山东省B-Victoria系流感病毒流行规律及基因特征,为B型流感疫苗的接种提供参考依据。  方法  对2019—2020流感监测年度监测数据进行分析,采用多阶段抽样方法随机抽取B-Victoria系流感病毒毒株进行基因序列的测定,采用Mega X软件的Muscle方法进行多序列比对,用Neighbor-Joining方法进行系统发育分析。  结果  2019—2020流感监测年度流感病毒以B-Victoria系和H3N2亚型为主; 20株流感病毒毒株的基因进化分析表明其与同期疫苗株B/Colorado/06/2017亲缘关系较远却与下一年度疫苗株B/Washington/02/2019关系较近且共同聚集在Clade1A(Δ3)分支上,与同期疫苗株B/Colorado/06/2017相比有13处氨基酸位点改变,其中有5处位于抗原决定簇,其最大变异率为1.91%;糖基化分析显示20株流感病毒毒株全部发生209位糖基化位点增加; 20株流感病毒毒株均未发现耐药位点突变。  结论  2019—2020流感监测年度推荐疫苗保护效果可能不理想,但山东省B-Victoria系流感病毒毒株对神经氨酸酶抑制剂依旧敏感。今后应继续密切关注B-Victoria系流感病毒的流行与基因变异情况,为B型流感病毒疫苗株的推荐及B型流感的防控提供依据。     

国产无硫柳汞三价流感病毒裂解疫苗上市后免疫原性和安全性观察

目的评价一种无硫柳汞的国产三价流感病毒裂解疫苗(TIV)上市后免疫原性和安全性。方法采用单中心、无对照设计在湖北省某乡镇招募≥6月龄健康受试者,接种本研究TIV,检测受试者免疫前和全程免疫后21-28d血清H1N1、H3N2、B型流感病毒血凝抑制(HI)抗体,观察接种后7d内不良反应。结果 591名受试者TIV免疫后H1N1、H3N2、B型流感病毒HI抗体阳转率分别为73.3%、86.3%、65.8%,抗体几何平均滴度(GMT)分别比免疫前增长10.9倍、20.2倍、8.0倍,抗体保护率分别为97.5%、100%、96.6%。720名受试者接种疫苗后总不良反应发生率为4.4%,其中局部反应、全身反应分别为0.8%、3.6%,未发现严重不良反应。结论本研究TIV应用于≥6月龄人群的免疫原性和安全性良好。     

1997年秋1998年春军队人群流感病毒抗体检测分析

目的监测军队人群流感病毒抗体水平,获知易感人群的比例,了解流感毒株的变异幅度及流行趋势.方法1997年秋和1998年春2次共采集954例军人血清,应用近4年8种国内及国际流感病毒代表株,以微量半加敏血凝抑制方法进行了抗体检测.结果军队人群中甲3亚型流感病毒抗体水平较高,A/山东/9/93(H3N2)、A/汉防/359/95(H3N2)抗体阳性率为89%～77%,抗体平均滴度(GMT)最高达58.该人群对近年来4种不同甲1亚型毒株的抗体水平存在很大差异.A/桂防/10/94(H1N1)抗体阳性率为84%(97秋)和89%(98春),GMT分别为90和134;最新国内代表株A/京防/53/97(H1N1)抗体阳性率明显偏低,为18%(97秋)和30%(98春),GMT分别为25和33.军队人群对乙型流感的抵抗力始终偏低,其B/京防/184/93、B/深防/12/97抗体阳性率为41%～55%,GMT为27～35.结论该部队人群甲3亚型株抗体已达饱和水平,提示抗原可能会发生变异,在一些地区引起流感中度流行甚或出现新亚型而引起大规模流行.H1N1毒株可能在军营中引起局部流行,对此应加强预测预报工作.     

广州市甲型H1N1流感病毒的持续进化变异监测

  目的  通过对H1N1流感病毒进行基因进化变异监测,为H1N1流感的科学防控提供研究数据。  方法  对广州市2017-2019年132株H1N1流感病毒进行血凝素(Hemagglutinin, HA)和神经氨酸酶(Neuraminidase, NA)基因测序,分析不同流行年度病毒的分子变异特点。  结果  2017-2019年广州市H1N1流行株HA和NA基因均聚为一簇,提示具有相同进化起源。2019年分离株依次由2017年分离株经2018年分离株过度进化而来,呈现较为明显的时间进化趋势。HA基因持续变异的抗原位点主要分布在91、181、202位,其中2018年H1N1流行株HA蛋白抗原位点的变异具有较为明显的多样性。2017和2019年流行株中有3株病毒发生NA蛋白H274Y神经氨酸酶抑制剂的耐药突变。  结论  广州市2017-2019年H1N1流行株与同年度疫苗株的匹配性较好,但病毒基因在持续进化和变异,在抗原位点和耐药位点上不同流行年份表现基因多态性。     

2005～2006年流感季节河北省甲3亚型流感病毒血凝素重链区基因变异分析

目的：研究2005～2006年流感流行期河北省分离的甲3（H3N2）亚型流感病毒株血凝素重链（HA1）的基因特性,了解H3N2亚型流感病毒株HA1基因的变异及其与流感流行的关系。方法：用狗肾（MDCK）细胞分离培养流感病毒,提取病毒核糖核酸（RNA）,采用RT-PCR法扩增病毒HA1基因,纯化产物进行核苷酸序列测定,用DNAStar软件作分析处理。结果：2005～2006年流感流行期在河北省分离到的H3N2亚型流感病毒株HA1与同时期的H3N2亚型流感疫苗株A/Calfornia/7/04相比其抗原性变异不大,核苷酸同源性为96.2%～98.2%,氨基酸同源性为98.7%～99.0%,3个位点发生了氨基酸替换,其中2个在抗原决定簇B区（188N〉D、193S〉F）,1个在受体结合位点（225D〉N）。结论：H3N2亚型流感病毒HA1尚未发生明显变异,与疫苗株同源性较高。人群对其已建立起较好的免疫屏障,这是河北省该流行期H3N2亚型活动水平低的主要原因。     

Effect of recent seasonal influenza vaccination on serum antibody responses to candidate pandemic influenza A/H5N1 vaccines: A meta-analysis

Recent studies have suggested that among those receiving seasonal influenza vaccine (SIV), reduced immunogenicity is observed in recently vaccinated (RV; within the past season or 2) persons when compared with those not recently vaccinated (NRV). We performed a meta-analysis to assess the effect of recent immunization with SIV on serum H5 hemagglutination inhibition (HAI) antibody responses after influenza A/H5N1 vaccination using data from a series of randomized controlled trials. The primary outcome was seroconversion measured by HAI assays following receipt of 2 doses of H5N1 vaccine. The geometric mean titer (GMT) of serum HAI antibody after vaccination was the secondary outcome. Analyses were performed using propensity score (PS) matching. The PS for each individual in the meta-analysis cohort was calculated using logistic regression and covariates included age, gender, race, antigen dose, adjuvant, statin use and vaccine manufacturer. 2015 subjects enrolled in 7 clinical trials were eligible for inclusion in the meta-analysis cohort; among these, 915 (45%) were RV. 901 RV subjects were matched (1:1) with replacement to a subject who was NRV. Subjects who received SIV within the previous season were significantly less likely to seroconvert following H5N1 vaccination (adjusted odds ratio 0.76; 95%CI 0.60–0.96; p = 0.024), and the GMT was 18% higher among NRV subjects (GM ratio of HAI antibody 1.18; 95%CI 1.04–1.33; p = 0.008). Further work is needed to better define the effects of, and mechanisms contributing to, reduced immune responses to H5N1 vaccine among RV subjects.     

Randomized comparative study of the serum antihemagglutinin and antineuraminidase antibody responses to six licensed trivalent influenza vaccines

Background

Serum antibody to the hemagglutinin (HA) surface protein of influenza virus induced by influenza vaccination is a correlate of protection against influenza. The neuraminidase (NA) protein is also on the surface of the virus; antibody to it has been shown to impair virus release from infected cells and to reduce the intensity of influenza infections in animal models and in humans challenged with infectious virus. Recently we have shown that NA inhibiting antibody can independently contribute to immunity to naturally-occurring influenza immunity in the presence of antibody to the HA.

Purpose

The present study was conducted to evaluate induction of antibody to the NA and the HA by commercially available influenza vaccines.

Methods

Healthy young adults were vaccinated with one of five commercially available trivalent inactivated vaccines or live influenza vaccine. Frequencies of serum antibody and fold geometric mean titer (GMT) increases four weeks later were measured to each of the three vaccine viruses (A/H1N1, A/H3N2, B) in hemagglutination-inhibition (HAI) and neutralization (neut) assays. Frequency and fold GMT increase in neuraminidase-inhibition (NI) antibody titers were measured to the influenza A viruses (A/H1N1, A/H3N2).

Results

No significant reactogenicity occurred among the vaccinated subjects. The Fluvirin inactivated vaccine induced more anti-HA antibody responses and a higher fold GMT increase than the other inactivated vaccines but there were no major differences in response frequencies or fold GMT increase among the inactivated vaccines. Both the frequency of antibody increase and fold GMT increase were significantly lower for live vaccine than for any inactivated vaccine in HAI and neut assays for all three vaccine viruses. Afluria inactivated vaccine induced more N1 antibody and Fluarix induced more N2 antibody than the other vaccines but all inactivated vaccines induced serum NI antibody. The live vaccine failed to elicit any NI responses for the N2 NA of A/H3N2 virus and frequencies were low for the N1 of A/H1N1 virus.

Conclusions

Trivalent inactivated influenza vaccines with similar HA dosage induce similar serum anti-HA antibody responses in healthy adults. Current inactivated vaccines all induce serum anti-NA antibody to the N1 and N2 NA proteins but some are better than others for N1 or N2. The live vaccine, Flumist, was a poor inducer of either anti-HA or anti-NA serum antibody compared to inactivated vaccine in the healthy adults. In view of the capacity for contributing to immunity to influenza in humans, developing guidelines for NA content and induction of NA antibody is desirable.     

江苏省新甲型H1N1流感疫苗免疫后抗体水平变化趋势研究

目的了解新甲型H1N1流感疫苗免疫前后人群抗体水平动态变化情况。方法随机选取部分疫苗接种人群为受试者,微量半加敏血凝抑制实验检测免疫前、免疫后1个月与免疫后3个月的血清抗体水平,计算抗体阳性率与抗体几何平均滴度(GMT),并进行统计学分析。结果免疫前、免疫后1个月与3个月抗体阳性率分别为13.64%(9.58%~18.61%)、83.63%(78.15%~88.20%)、77.06%(71.09%~82.32%),GMT分别为9.36(8.30~10.56)、122.53(100.29~149.70)、96.07(77.85~118.54)。免疫前与免疫后1个月、3个月后相比,抗体阳性率与GMT差异均有统计学意义。免疫后1个月与免疫后3个月两者差异均无统计学意义。结论本研究所用甲型H1N1流感病毒裂解疫苗免疫后抗体水平明显升高,且维持时间较长。     

2010年长沙市甲型H1N1流感大流行血清学流行病学调查

目的掌握2010年长沙市甲流流行期间不同时点及人群甲型H1N1型流感血清流行病学特征。方法 2010年1月、3月、8月使用多阶段随机抽样方法在全市5个区,按照0~、6~、16~、25~和60~岁5个年龄组随机抽取一定数量的研究对象开展三次横断面调查,每次均对调查对象进行问卷调查,并采集静脉血进行甲型H1N1流感血凝抑制试验。结果 5个年龄组人群中,6~岁组和16~岁组甲流血清抗体阳性率都随着时间的推移呈现下降趋势,以6~岁组的下降幅度较大,其抗体滴度几何均数(GMT)下降幅度也较大。6个职业组人群中,学生和医务人员组甲流血清抗体阳性率都随着时间的推移呈现下降趋势,学生组下降幅度较大。不同性别间血清抗体阳性率和GMT差异均无统计学意义(P0.05)。综合三次调查结果,接种甲流疫苗后,人群的甲流血清抗体阳性率达到55.53%,为未接种流感疫苗人群的2.15倍;抗体GMT达到44.62,为未接种甲流疫苗人群的3.74倍。结论 2010年长沙市甲流流行趋势趋于缓和,初步形成免疫屏障;学生和医务人员是感染甲流的高风险人群;接种甲流疫苗后人群有较高的抗体阳性率,但是抗体水平下降较快;接种甲流疫苗对人群有一定的保护作用,应加强对60岁及以上人群甲流疫苗的接种和补种。     

Neutralizing antibody but not hemagglutination antibody provides accurate evaluation for protective immune response to H5N1 avian influenza virus in vaccinated rabbits

In order to develop an animal model and an assay method to evaluate protective immune response to H5N1 avian influenza vaccination, H5N1 avian influenza vaccine was prepared. New Zealand rabbits were assigned to receive two doses of vaccine with different hemagglutinin (HA) dosage. The sera from vaccinated rabbits was evaluated to determine antibody titer and specificity using different tested methods including hemagglutination inhibition assay (HI), neutralizing assay (NT), cross-HI assay, cross-single immunodiffusion assay and cross-neutralization assay. The titer of HI antibody from rabbits immunized with different doses of HA were no less than 1:40 among groups 14 days after the first immunization. Whereas the NT antibody titer was less than 1:10 among groups 14 days after the first immunization. NT antibodies can be detected 14 days after the second immunization in rabbits immunized at HA doses higher than 6 μg, and the NT antibody titers were equal to or higher than 1:40. A good concentration-dependent NT antibody response can be detected in the vaccinated rabbits 14 days after the second immunization, and in contrast, no concentration-dependent relationship can be seen for HA antibody. The cross-HI test showed sera from vaccinated rabbits could cross react with influenza A H5N1 virus with the titers higher than 1:40. No cross reaction among different types (influenza A/H1N1 virus, influenza A/H3N2 virus, influenza B virus and influenza A/H5N1 virus) can be detected in the sera using the single immunodiffusion assay and using NT antibody test. This showed NT antibody test was demonstrated as a more accurate assay method for evaluating vaccination and quality of the vaccine than HI antibody test.     

Influenza virus subtype cross-reactivities of haemagglutination inhibiting and virus neutralising serum antibodies induced by infection or vaccination with an ISCOM-based vaccine.

In order to study the levels of cross-reactivity of the influenza virus-specific antibody response upon infection or vaccination, usually hemagglutination inhibition assays are performed. In the present study post-infection ferret sera and serum samples obtained from cynomolgus macaques which were vaccinated with an ISCOM preparation based on the influenza virus strain A/Netherlands/18/94 (H3N2) were analyzed for cross-reactivity in the hemagglutination inhibition assay and in virus neutralization assays. It was shown that the cross-reactivity of the antibodies induced upon vaccination or infection with influenza virus proved to be more limited in the virus neutralization assay than in the hemagglutination assay. The strong antibody response induced by vaccination with the A/Netherlands/18/94-ISCOM preparation was shown to be cross-reactive with recent influenza virus strains, which were isolated since 1992, but not with older strains.     

东莞市2010年新型H1N1流感病毒实验结果分析

目的:了解东莞市2010年新型H1N1流感病毒的流行情况及疫苗免疫效果,为新型H1N1流感病毒的防控提供依据。方法:采集临床疑似流感病例的咽拭子分泌物,用荧光定量RT-PCR方法检测核酸。采集接种新型H1N1疫苗前后双份血清,用血凝抑制实验检测新型H1N1抗体滴度。结果:全年共检测1811份样品,新型H1N1阳性103例,阳性率为5.39%,男女之间的检测阳性率有显著性差异,女性高于男性(χ2=4.351,P=0.037)。病例数最多的年龄组为15岁～24岁和25岁～40岁,分别为32例和26例。发病高峰在1月份,阳性病例数为58份,占全年总阳性例数的56.31%。疫苗接种前后,几何平均滴度(GMT)增长14.09倍,免疫成功率为76.32%。结论:2010年东莞市新型H1N1流感病毒流行情况较2009年发生较大的改变,新型H1N1流感疫苗有很好的免疫效果,能使大部分接种对象产生有效的抗体。     

深圳市2006年流行性感冒流行特征分析

目的了解深圳市流感流行动态,探索流行规律,为流感的防治提供科学依据。方法每周统计监测点流感样病例（ILI）数据,采集ILI鼻咽拭子标本,用鸡胚和MDCK细胞同时进行流感病毒分离,采用血凝抑制实验进行流感病毒型别鉴定和测定血清抗体。结果深圳市全年共报告流感样病例（ILI）112651例,占监测门急诊就诊病例总数的6.27%;共分离出病毒154株,病毒分离率为5.33%,其中H1N1亚型103株、B（Victoria）型48株、H3N2亚型3株;共报告流感样病例暴发疫情25起,88%集中在中小学校;一般人群血清抗体GMT水平,甲型均低于1∶40,乙型均低于1∶20。结论深圳市流感监测结果可靠,2006年流感流行高峰为3～6月,H1N1、B（Victoria）为主要流行株。一般人群各型流感抗体水平均偏低。     

进口与国产流感疫苗血清学免疫效果对比

目的 了解进口流感疫苗与国产流感疫苗对中国健康人群的血清学免疫效果，为流感疫苗的使用选择提供科学依据。方法 选择中国北方较为广泛使用的进口和国产2种疫苗，分别接种于2组健康人群，在免疫后不同时间，检测其抗体滴度，计算抗体保护率。结果 仅乙型抗体几何平均滴度(GMT)在免疫后150d，2组差异有显著性(t＝2．0339，P＜0．05)，2种疫苗在免疫后各时期，其抗体保护率差异均无显著性。甲l型和甲2型抗体GMT在免疫后各时间差异无显著性。结论 2种疫苗血清学免疫效果基本相同。