嘉兴市2011—2012年乙型流感监测与HA1序列分析

[目的]了解2011—2012年嘉兴市乙型流感的流行状况及病毒序列特性、变异特点和WHO推荐流感疫苗株对人体的保护情况。[方法]将采集的流感样病例的咽拭子标本用MDCK细胞培养分离流感病毒,用标准血清及荧光定量RT-PCR方法鉴定。随机选取6株乙型流感病毒株进行HA1基因核苷酸序列测定,并进行特性分析。[结果]2011—2012年嘉兴市乙型流感病毒Victoria系和Yamagata系同时存在。随机抽取4株Victoria系和2株Yamagata系毒株,在糖基化位点上没有变化。4株Victoria系毒株核苷酸同源性为98.6%～99.7%,氨基酸同源性为98.8%～100.0%,其中2株与2009—2012年疫苗株相比,在L58P、N129S、I146V、N171D发生了氨基酸的替换。2株Yamagata系毒株核苷酸和氨基酸同源性为99.4%,与2012—2013年疫苗株极为接近。[结论]嘉兴市流行的Victoria系乙型流感病毒与2009—2012年疫苗代表株同源性较高,当年度的流感疫苗株对本市Victoria系乙型流感病毒流行的防治有一定保护作用。但本地同时也还活跃着Yamagata系的乙型流感病毒,当年度的流感疫苗株对Yamagata系乙型流感病毒不能提供最佳保护。     

新余市2013年-2014年B型Yamagata系流感病毒HA1基因特性分析

目的了解2013年-2014年新余市Yamagata系乙型流感病毒的序列特性和变异特点,分析WHO推荐流感疫苗株对人体的保护情况。方法选取新余市2013年-2014年通过狗肾传代细胞(MDCK)培养分离到的Yamagata系乙型流感毒株9株,提取病毒RNA,反转录-聚合酶链式反应(RT-PCR)扩增HA1基因片段,对序列进行处理和特性分析。结果 2013年-2014年的乙型流感病毒均为B型Yamagata系。9株流感毒株HA1区与疫苗推荐株B/Wisconsin/01/2010的核苷酸同源性为97.8%~99.4%,氨基酸替换数为3个~4个,其中8株均在3个相同的氨基酸位点发生变异;与代表株B/Yamagata/16/1988的核苷酸同源性为94.4%~96.2%。B/Jiangxi Yushui/1221/2014与疫苗株B/Massachusetts/02/2012的核苷酸同源性为99.3%,氨基酸替换数为3个。结论新余市2013年-2014年B型Yamagata系流感病毒都发生了抗原性变化,WHO推荐的2011年-2012年疫苗对88.89%的B型Yamagata系流感仍有预防效果,当年度的疫苗株能很好地预防另外11.11%流感的流行。     

2007年江西省乙型流感病毒流行的分子基础

目的 了解江西省2007年乙型流感病毒流行情况的分子基础.方法 采集监测医院和疑似流感疫情的流感样病例鼻咽拭子标本进行流感病毒分离,对分离到的B型流感病毒进行核酸的提取,采用逆转录-聚合酶链反应(RT-PCR)扩增病毒HA1基因后进行核苷酸序列测定,用DNAStar5.0、BioEdit(Version5.0)、Mega生物软件对测序结果进行分析处理,推导出氨基酸序列,进行基因特性分析.结果 2007年分离到B型流感病毒91株,其中68株Yamagata系和23株Victoria系;6株Yamagata系和4株Victoria系B型流感病毒分别与WHO推荐的疫苗株B/Shanghai/361/2002(Yamagata系)和B/Malaysia/2506/2004(Victoria系)的HA1序列比对,结果为:Yamagata系B型流感病毒HA1区域核苷酸平均替换数为23.3个,平均点突变率为2.30%,氨基酸替换数在7～9个,同源性为95.2%～96.3%,所有毒株均在6个相同的氨基酸位点发生了相同的替换;Victoria系B型流感病毒HA1区域核苷酸平均替换数为8.5个,平均点突变率为0.84%,氨基酸替换数在3～4个,同源性为98.95%～99.48%,所有毒株均在3个相同的氨基酸位点发生了相同的替换.结论 2007年Victoria系B型流感病毒HA1基因特性有所改变,疫苗仍有预防效果,但是B型流感流行趋势发生了改变,Yamagata系比Victoria系更活跃,B/Malaysia/2506/2004(Victoria系)疫苗推荐株对江西省B型流感保护效果不佳.     

甘肃省流感季节性流行特征及病原变迁研究

目的 分析甘肃省流感季节性流行特征,为制定适宜的科学防控措施,优化流感疫苗预防接种指导意见提供依据。方法 收集2010年第1周至2016年第40周甘肃省分周流感病原学监测数据, χ²检验比较不同季节流感病毒核酸检测阳性率及病原型别构成,并用时间序列季节性分解方法分析流感病毒总阳性率及各型别阳性率的季节性流行特征。结果 共检测标本59 791份,流感病毒核酸阳性8 501份,阳性率14.22%,病毒型别以A（H1N1）pdm09型、A（H3N2）型和B型为主,占所有阳性标本的98.76%。不同季节流感病毒阳性率分别为春季15.12%、夏季0.98%、秋季4.02%、冬季24.26%。不同季节病毒型别构成,秋冬季以A（H3N2）型居多,春季以B型为主。甘肃省季节性流感呈典型的单峰型分布,流行高峰多出现在12月至次年1月,高峰起始时间以A（H3N2）型最早,其次是A（H1N1）pdm09型,B型最晚。结论 流感季节性流行高峰出现时间、持续时间与主要优势株的型别构成有关。甘肃省流感疫苗接种时间应为每年10月份,以便在流行期提供有效保护。     

2008-2012年江西省乙型流感病毒HA1基因特性分析

摘要:目的　了解2008-2012年江西省分离的B型流感病毒株HA1基因变异特征。方法　采集监测医院和疑似流感疫情的流感样病例鼻咽拭子标本进行流感病毒分离,对分离到的B型流感病毒进行核酸的提取,采用逆转录－聚合酶链反应（RT-PCR）扩增病毒基因后进行核苷酸序列测定,用DNAStar5.0、Mage对测序结果进行分析处理,推导出氨基酸序列,进行基因特性分析。结果　10株Yamagata系B型毒株HA1基因之间的同源性为97.5%～100.0%,14株Victoria系B型毒株HA1基因之间的同源性为97.0%～99.9%。我省2008年分离的Yamagata系流感病毒与疫苗株间有5～7个变异,2009-2011年分离的Victoria系流感病毒与疫苗株间有5～7个变异,2012年分离的Yamagata系流感病毒与疫苗株间有1～4个变异,其中最多只有1个变异位于抗原决定簇。结论　2008-2012年江西省B型流感HA1基因未发生明显变异,WHO推荐的B型流感疫苗株对我省流行的B型流感具有保护作用。     

2015-2017年盐城市乙型流感病毒HA1、NA基因分子特征

  目的   对盐城市2015-2017年流行的乙型流感病毒血凝素(hemagglutinin, HA)和神经氨酸酶(neuraminidase, NA)基因进行分子进化特征研究。   方法   将盐城市2015-2017年流感监测哨点医院以及流感暴发点采集的流感样病例咽拭子标本进行核酸、病毒分离检测定型, 对选取的18株乙型流感病毒分离株采用一步法RT-PCR方法扩增其HA1基因和NA基因, 扩增产物经纯化测序, 采用生物信息软件从核苷酸、氨基酸以及分子进化层面对毒株进行分子特征分析。   结果   盐城市2015-2017年分离的乙型流感病毒HA1基因和NA基因聚类的分支关系基本一致, 2015年Yamagata系毒株位于Yamagata Clade 3分支, 属Phuket/3073类毒株; 2016-2017年Victoria系毒株分布于Victoria Clade 1A分支, 属Brisbane/60类毒株。Yamagata系所有毒株在190-helix抗原表位均发生了D196N位点的变异; Victoria系毒株共涉及2个抗原表位, 120-loop抗原表位的117、129位点, 190-helix抗原表位的197、199位点。盐城株未发生系内、系间重配。18株分离株未发生NA蛋白酶活性位点以及耐药位点的变化。   结论   2015年Yamagata系毒株与疫苗株B/Phuket/3073/2013匹配性较好。2016-2017年Victoria系毒株HA1和NA抗原基因变异位点在积累, 这些变异位点的积累很可能会导致流感病毒发生实质性的抗原性的漂移, 降低与流感疫苗株的匹配度, 减弱流感疫苗的保护作用。     

2015-2016年唐山市流感病原学特征及B型流感病毒HA基因进化分析

目的了解2015-2016年唐山市流感流行季节的流感病原学特征,并对B型流感病毒HA基因进行进化分析,为制定有效防治措施提供科学依据。方法采集哨点医院流感样病例咽拭子标本,采用实时荧光PCR检测流感病毒RNA,并对3株B型流感病毒进行扩增测序分析。结果 2015-2016年采集的1 391例患者的标本中检出阳性275例,检出率为19.77%,其中B型147例,H3N2亚型102例,新甲H1N1亚型26例。流感季峰值出现在2016年第2周和第13周。监测的流感样病例以5～14岁病毒检出率最高,为28.94%。HA基因进化分析显示,唐山市B型流感病毒分为B/Victoria和B/Yamagata两大谱系,其中2株B/Victoria属于进化1A分支,1株B/Yamagata属于进化3分支,与WHO推荐的疫苗株B/Brisbane/60/2008相比B/Victoria系毒株最具代表性的氨基酸替换发生在I117V和N129D(1A分支),与疫苗株B/Phuket/3073/2013(B/Yamagata 3分支)相比B/Yamagata有3个位点发生替换。结论 2015-2016年唐山市流感流行季节流感的流行主要以B型流感病毒为主,并有明显的季节性,主要易感人群为儿童。应加强对流感病毒的监控并积极推广疫苗的接种。2015-2016年唐山市B型流感毒株发生明显变异,连续的分子学监测对该市的疫苗接种政策有重要意义。     

厦门地区17株B型流感病毒的基因组测序分析

目的了解2015年厦门地区17株B型流感病毒的基因组序列特征。方法利用高通量测序对17株B型流感病毒进行全基因组序列测定,并分析基因进化特性。结果成功获得17株B型流感病毒的全基因组序列,其中Yamagata系病毒16株,Victoria系病毒1株。与WHO推荐的疫苗株B/Massachusetts/2/2012比较,Yamagata系病毒的HA和NA氨基酸序列均发生了变异。结论厦门地区人群中流行的乙型流感病毒的抗原性和基因特性在逐渐发生变异,HA和NA基因序列部分位点与疫苗株存在差异,可能导致其抗原性发生改变。     

2004～2006年江西省乙型流感病毒HA1基因特性分析

目的：了解江西省2004～2006年分离的B型流感病毒株HA1基因变异特征。方法：采集监测医院和疑似流感疫情的流感样病例鼻咽拭子标本进行流感病毒分离,对分离到的B型流感病毒进行核酸的提取,采用逆转录-聚合酶链反应（RT-PCR）扩增病毒基因后进行核苷酸序列测定,用DNAStar5.0、BioEdit（Version5.0）、Mage生物软件对测序结果进行分析处理,推导出氨基酸序列,进行基因特性分析。结果：2004年和2005年分离到的B型流感病毒均为B型的Yamagata系;2006年以Victoria系为优势株,但有Yamagata系的活动。9株Yamagata系B型流感病毒HA1区域核苷酸序列长度均为1014 bp,未发现核苷酸的丢失和插入,与疫苗推荐株B/Shanghai/361/2002 HA1区相比较,不同毒株氨基酸同源性为96.4%～97.3%,替换数在10～11个,所有毒株均在9个相同的氨基酸位点发生了相同的替换,在196位增加了一个糖基化位点。12株Victoria系B型流感病毒HA1区域核苷酸序列长度均为1017 bp,未发现核苷酸的丢失和插入,与疫苗推荐株B/Malaysia/2506/2004的HA1区相比较,不同毒株氨基酸同源性为98.4%～99.5%,替换数在2～4个,所有毒株均在2个相同的氨基酸位点发生了相同的替换,在197位增加了一个糖基化位点。结论：江西省2004～2006年Yamagata系B型流感病毒HA1基因特性已发生改变,从基因水平说明Yamagata系B型流感病毒抗原性发生了改变。2006年Victoria系B型流感病毒HA1基因特性有所改变,疫苗仍有预防效果。     

2008-2009年珠海市乙型流感病毒HA1基因特性分析

目的了解珠海市2008-2009年乙型流感病毒HA1基因变异情况。方法按照采样时间,选取珠海市2008-2009年每月用狗肾传代细胞(MDCK)培养分离到的第1、2株乙型流感毒株共25株,没分离到毒株的月份不选,提取病毒RNA,RT-PCR扩增HA1基因片段,产物纯化测序,推导氨基酸序列,进行基因进化特性分析。结果 2008年珠海市乙型流感毒株在8月达到分离高峰,晚于A型流感毒株分离高峰时间7月,2009年其在4月达分离高峰,早于A型流感毒株分离高峰时间5月。2008-2009年珠海市流行的乙型流感病毒优势株为Victoria系病毒。与北半球国际疫苗株B/Florida/4/2006 like-virus(GenBank序列号CY033876.1)相比,2008-2009年珠海市流行的Yamagata系乙型流感病毒HA1片段有7个氨基酸位点发生替换:分别是103 K→R,212D→N,其中08-1267、09-0233和09-0240毒株的218N→S,08-190毒株的123P→A、245S→G、270P→S,除08-190外另5株毒株的181N→Y、245S→D,氨基酸同源性高于97%。其中有2个参与构成抗原决定簇的氨基酸位点发生替换,没有发生病毒抗原漂移。Victoria系毒株与疫苗代表株的同源性低于89%。结论 2008-2009年珠海市流行的Yamagata系乙型流感病毒与疫苗代表株同源性极高,本年度的流感疫苗株对珠海市乙型流感病毒流行的防治起了一定作用。2008-2009年珠海市流行的乙型流感病毒优势株属Victoria系,故本年度的流感疫苗株不能对珠海地区流行的乙型流感提供最佳保护。珠海市2008年乙型流感病毒流行时间较长,2009年流行高峰提前可能与此有关。     

Effectiveness of seasonal influenza vaccine in Australia, 2015: An epidemiological,antigenic and phylogenetic assessment

BackgroundA record number of laboratory-confirmed influenza cases were notified in Australia in 2015, during which type A(H3) and type B Victoria and Yamagata lineages co-circulated. We estimated effectiveness of the 2015 inactivated seasonal influenza vaccine against specific virus lineages and clades.MethodsThree sentinel general practitioner networks conduct surveillance for laboratory-confirmed influenza amongst patients presenting with influenza-like illness in Australia. Data from the networks were pooled to estimate vaccine effectiveness (VE) for seasonal trivalent influenza vaccine in Australia in 2015 using the case test-negative study design.ResultsThere were 2443 eligible patients included in the study, of which 857 (35%) were influenza-positive. Thirty-three and 19% of controls and cases respectively were reported as vaccinated. Adjusted VE against all influenza was 54% (95% CI: 42, 63). Antigenic characterisation data suggested good match between vaccine and circulating strains of A(H3); however VE for A(H3) was low at 44% (95% CI: 21, 60). Phylogenetic analysis indicated most circulating viruses were from clade 3C.2a, rather than the clade included in the vaccine (3C.3a). VE point estimates were higher against B/Yamagata lineage influenza (71%; 95% CI: 57, 80) than B/Victoria (42%, 95% CI: 13, 61), and in younger people.ConclusionsOverall seasonal vaccine was protective against influenza infection in Australia in 2015. Higher VE against the B/Yamagata lineage included in the trivalent vaccine suggests that more widespread use of quadrivalent vaccine could have improved overall effectiveness of influenza vaccine. Genetic characterisation suggested lower VE against A(H3) influenza was due to clade mismatch of vaccine and circulating viruses.     

Lineage-matched versus mismatched influenza B vaccine effectiveness following seasons of marginal influenza B circulation

BackgroundSeveral countries have recently transitioned from the trivalent inactivated influenza vaccine (TIV) to the quadrivalent inactivated influenza vaccine (QIV) in order to outweigh influenza B vaccine-mismatch. However, few studies thus far evaluated its benefits versus the TIV in a systematic manner. Our objective was to compare the QIV VE with lineage-mismatched TIV VE.MethodsWe estimated the 2015–2016, 2017–2018, 2019–2020 end-of season influenza B VE against laboratory-confirmed influenza-like illness (ILI) among community patients, using the test-negative design. VE was estimated for pre-determined age groups and for moving age intervals of 15 years.ResultsSince 2011–2012 season, alternate seasons in Israel were dominated by influenza B circulation. Compared with the lineage-mismatched TIV used during the 2015–2016 and 2017–2018 seasons, the 2019–2020 QIV showed the highest all-ages VE, with VE estimates of 56.9 (95% CI 30.1 to 73.4), 16.5 (95% CI –22.5 to 43.1) and ?25.8 (95% CI ?85.3 to 14.6) for the 2019–2020, 2017–2018 and 2015–2016 seasons, respectively. The 2019–2020 VE point estimated were the highest for the 0.5–4, 5–17 and 18–44 years age groups and for more 15-year age intervals as compared to the other seasons.ConclusionsOur results support the rapid transition from the TIV to the QIV.     

Molecular epidemiology and genetic characterization of influenza B virus in Lebanon during 2016–2018

BackgroundInfluenza B viruses are a major cause of serious acute respiratory infections in humans.MethodsNasopharyngeal swabs were collected from subjects with influenza-like illness during October 2016–June 2018 and screened for influenza A and B. The hemagglutinin (HA) and neuraminidase (NA) genes of the Lebanese influenza B specimens were sequenced and phylogenetically compared with the vaccine strains and specimens from the Eastern Mediterranean Region and Europe.ResultsInfluenza A and B viruses co-circulated between October and May and peaked between January and March. During the 2016–2017 season, A/H3N2 (33.4%) and B/Yamagata (29.7%) were the predominantly circulating viruses followed by B/Victoria and A/H1N1pdm09 viruses. During the 2017–2018 season, A/H3N2 (31.5%) and A/H1Npdm09 (29.3%) were most prevalent with co-circulation of B/Yamagata and to a lesser extent B/Victoria viruses. The B/Yamagata specimens belonged to clade-3 while the B/Victoria belonged to clade-1A. None of the analyzed specimens had a mutation known to confer resistance to NA inhibitors (NAIs).ConclusionMultiple subtypes of influenza co-circulate each year in Lebanon with a peak between January and March. The trivalent vaccine included a B/Victoria strain which mismatched the B/Yamagata lineage that predominated during the study period, highlighting the importance of quadrivalent vaccines.     

Public health impact of including two lineages of influenza B in a quadrivalent seasonal influenza vaccine

The annual trivalent influenza vaccine (TIV) includes viruses representing three influenza strains - one A/H1N1, one A/H3N2, and one B, although two antigenically distinct lineages of influenza B (Victoria and Yamagata) co-circulate annually in the United States. Predicting which lineage of influenza B will predominate during a season is challenging, and cross-protection by immunization against the other lineage is expected to be low. One proposed alternative is to produce a quadrivalent influenza vaccine (QIV) including an influenza B virus from each of the two circulating lineages. We estimated the additional public health benefit of QIV compared with TIV by calculating the expected impact on influenza-related health outcomes (illness, hospitalization, and death) over ten influenza seasons (1999/2000-2008/2009). We included data on the annual incidence of influenza-associated outcomes, virologic circulation, vaccine coverage, and vaccine effectiveness. We also considered annual vaccine production capacity, since available resources would have produced four vaccine viruses instead of three, potentially resulting in fewer doses of QIV. Use of QIV could have reduced annual cases (range: 2200-970,000), hospitalizations (range: 14-8200), and deaths (range: 1-485) in the US. During earlier seasons, adjusting production capacity for a fourth virus in QIV could have resulted in reduced overall influenza vaccine availability and net increases in influenza-associated outcomes. However, in recent seasons, the expected supply of QIV is likely to exceed the doses of vaccine actually administered. The potential net impact of QIV on influenza-associated outcomes is expected to vary between seasons, depending on annual variability in the incidence of influenza caused by the two influenza B lineages, vaccine coverage, and effectiveness. The additional protection provided by including a second lineage of influenza B could result in a modest reduction in influenza-associated outcomes.     

Safety and immunogenicity of a seasonal quadrivalent influenza vaccine (GC3110A) in healthy participants aged ≥ 65 years

BackgroundSeasonal Influenza is still considered associated with seasonal morbidity and hospitalization in the elderly population. The World Health Organization (WHO) recommended seasonal quadrivalent influenza vaccine (QIV) to reduce burden of two currently circulating influenza B lineages. Until 2019 Korean National Immunization Program (NIP) recommended trivalent influenza vaccine (TIV) after ongoing debates on cost effectiveness of QIV for elderly population. Although influenza vaccine only showed modest effect on reducing influenza in elderly, this study aimed to evaluate the immunogenicity and safety of inactivated QIV in healthy participants ≥ 65 years of age.MethodsA total of 274 healthy participants aged ≥ 65 years received a QIV. Seroconversion-based vaccine efficacy of 4 strains of seasonal influenza was assessed 21 days after vaccination and adverse events were monitored until 180 days after vaccination.ResultsThe percentages of participants seroconverted after vaccination on HI antibody against each strain were 36.5% (99/271) to A/H1N1, 47.6% (129/271) to A/H3N2, 40.6% (110/271) to B Yamagata, and 49.1% (133/271) to B Victoria. The percentages of participants seroprotected after vaccination on HI antibody against each strain were 81.2% (220/271) to A/H1N1, 98.5% (267/271) to A/H3N2, 95.2% (258/271) to B Yamagata, and 93.7% (254/271) to B Victoria. There was no serious adverse event (SAE) related with the study vaccine.ConclusionThe quadrivalent split influenza vaccine is expected to offer seroprotection against influenza A and both influenza B lineages even in the elderly population.     

Development of high yield reassortants for influenza type B viruses and analysis of their gene compositions

A critical step in producing the annual inactivated influenza vaccine is the development of high yield (hy) seed viruses by reassortment for improved growth in ovo. Although hy reassortants for type A influenza viruses have been developed for many years, hy B influenza reassortant virus development for vaccine production has proven difficult. In this study, we have developed fourteen hy influenza type B reassortants as vaccine candidate strains with B/Lee/40 as the donor virus. Upon characterization by the Influenza Division at the Centers for Disease Control and Prevention (CDC) and the verification of HA by sequencing, all B reassortants were found to be antigenically indistinguishable from the wild type (wt) parents and suitable for vaccine production. However, only one hy reassortant seed virus from this group was used by a manufacturer for vaccine production. In general, hy reassortants showed an increase in hemagglutination (HA) titers over their wt parents by approximately 8 fold (range 1–32 fold). Gene compositions of the hy B reassortants were analyzed by restriction fragment length polymorphism (RFLP) and the wt origin of the HA and neuraminidase (NA) were confirmed. However, in contrast to hy A reassortants which require the M gene (hy donor A/PR/8/34) for high yield, all fourteen hy B reassortants obtained the NP gene from the hy donor strain (B/Lee/40). The parental source for the remaining genes varied among the hy B reassortants. The results indicate that the B/Lee/40 NP and PB1 gene segments are important contributors to high yield growth in influenza B reassortant viruses for both Yamagata and Victoria lineages. The B/Lee/40 PB2 gene along with wt NS gene also contributed to the improved growth for hy reassortants of Yamagata lineage.     

A randomized,double-blind,non-inferiority trial comparing the immunogenicity and safety of two seasonal inactivated influenza vaccines in adults

BackgroundTo enhance the production and availability of influenza vaccines in different regions of the world is paramount to mitigate the global burden of this disease. Instituto Butantan developed and manufactured an embryonated egg-based inactivated split-virion trivalent seasonal influenza vaccine as part of a technology transfer partnership with Sanofi Pasteur.MethodsThis is a phase IV, randomized, double-blind, active-controlled, multicenter clinical trial including adults 18–60 and > 60 years recruited during the 2019 southern hemisphere influenza season. Subjects were randomized 1:1 to receive either the Sanofi Pasteur Trivalent Seasonal Influenza Vaccine (SP-TIV) or Instituto Butantan Trivalent Seasonal Influenza Vaccine (IB-TIV). Hemagglutinin inhibition antibody titers were assessed pre-vaccination and 21 days post-vaccination.Results624 participants were randomized and vaccinated. In both intention-to-treat and per-protocol analysis, non-inferiority of the SP-TIV versus IB-TIV was demonstrated for the three influenza strains. In the per-protocol analysis, the SP-GMT/IB-GMT ratios for H1N1, H3N2, and B were 0.9 (95%CI, 0.7–1.1), 1.2 (95%CI, 1.0–1.4), and 1.1 (95%CI, 0.9–1.3), respectively. Across vaccination groups, the most common adverse reactions (AR) were limited to the injection-site, including pain and tenderness. The majority of the ARs were graded 1 and/or 2 and lasted less than one day. No serious adverse reaction was observed.ConclusionThis study demonstrated the non-inferiority of the immunogenicity of a single-dose of Instituto Butantan versus a single dose of the Sanofi Pasteur Seasonal Trivalent Influenza Vaccine in adults. Both vaccines were well tolerated and presented similar safety profiles.     

广东省1991-2004年乙型流感监测结果分析

[目的]分析1991—2004年广东省乙型流感病毒抗原变异和流行情况。[方法]用9~11日龄鸡胚和(或)MDCK细胞分离流感病毒,病毒鉴定用常量红细胞凝集抑制法(HI);人血清流感抗体检测用微量半加敏红细胞凝集抑制法。[结果]广东省一直有乙型流感流行,并从人群中分离到流感病毒2 916株,乙型流感病毒占23.3%。乙型流感病毒两大谱系交替为优势株,除1994、1997及2002年以Victoria系为主外,其余各年以Yamagata系为主。乙型流感病毒抗原性不断发生漂移,历年一般人群血清乙型流感抗体检测阳性率在28.3%~73.9%。[结论]1991—2004年广东省乙型流感病毒存在差异较大的两个谱系,病毒谱系的轮换和抗原漂移导致乙型流感不断流行。