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Genetic characterization of influenza A(H3N2) viruses circulating in coastal Kenya, 2009-2017.

2009-2017年肯尼亚沿海流行的甲型 H3N2 流感病毒的遗传特征。

  • 影响因子:3.20
  • DOI:10.1111/irv.12717
  • 作者列表:"Owuor DC","Ngoi JM","Otieno JR","Otieno GP","Nyasimi FM","Nyiro JU","Agoti CN","Chaves SS","Nokes DJ
  • 发表时间:2020-01-13
Abstract

BACKGROUND:Influenza viruses evolve rapidly and undergo immune driven selection, especially in the hemagglutinin (HA) protein. We report amino acid changes affecting antigenic epitopes and receptor-binding sites of A(H3N2) viruses circulating in Kilifi, Kenya, from 2009 to 2017. METHODS:Next-generation sequencing (NGS) was used to generate A(H3N2) virus genomic data from influenza-positive specimens collected from hospital admissions and health facility outpatients presenting with acute respiratory illness to health facilities within the Kilifi Health and Demographic Surveillance System. Full-length HA sequences were utilized to characterize A(H3N2) virus genetic and antigenic changes. RESULTS:From 186 (90 inpatient and 96 outpatient) influenza A virus-positive specimens processed, 101 A(H3N2) virus whole genomes were obtained. Among viruses identified in inpatient specimens from 2009 to 2015, divergence of circulating A(H3N2) viruses from the vaccine strains A/Perth/16/2009, A/Texas/50/2012, and A/Switzerland/9715293/2013 formed 6 genetic clades (A/Victoria/208/2009-like, 3B, 3C, 3C.2a, 4, and 7). Among viruses identified in outpatient specimens from 2015 to 2017, divergence of circulating A(H3N2) viruses from vaccine strain A/Hong Kong/4801/2014 formed clade 3C.2a, subclades 3C.2a2 and 3C.2a3, and subgroup 3C.2a1b. Several amino acid substitutions were associated with the continued genetic evolution of A(H3N2) strains in circulation. CONCLUSIONS:Our results suggest continuing evolution of currently circulating A(H3N2) viruses in Kilifi, coastal Kenya and suggest the need for continuous genetic and antigenic viral surveillance of circulating seasonal influenza viruses with broad geographic representation to facilitate prompt and efficient selection of influenza strains for inclusion in future influenza vaccines.

摘要

背景: 流感病毒进化迅速,并经历免疫驱动的选择,特别是在血凝素 (HA) 蛋白中。我们报道了影响肯尼亚 Kilifi 循环的 A (H3N2) 病毒抗原表位和受体结合位点的氨基酸变化,2009年 2017年。 方法: 使用下一代测序 (NGS) 生成 A (H3N2) 从医院入院和医疗机构门诊患者中收集的流感阳性标本的病毒基因组数据,表现为急性呼吸系统疾病到 Kilifi 健康和人口监测系统内的医疗机构。利用全长 HA 序列表征 A (H3N2) 病毒的遗传和抗原变化。 结果: 从处理的 186 例 (90 例住院和 96 例门诊) 甲型流感病毒阳性标本中,获得 101 例 A (H3N2) 病毒全基因组。在住院标本 2009年 2015年鉴定的病毒中,来自疫苗株 A/Perth/16/2009 、 A/Texas/50/2012 的循环 A (H3N2) 病毒的分歧, 和 A/瑞士/9715293/2013 形成了 6 个遗传分支 (A/Victoria/208/2009-like,3B,3C,3 C.2a,4 和 7)。在门诊标本 2015年 2017年鉴定的病毒中,来自疫苗株 A/Hong Kong/4801/2014 的循环 A (H3N2) 病毒的分歧形成了分支 3 C.2a,小分支 3 C.2a2 和 3 C.2a3, 和亚组 3 C.2a1b。几个氨基酸置换与循环中 A (H3N2) 菌株的持续遗传进化相关。 结论: 我们的结果表明目前在 Kilifi 中循环的 A (H3N2) 病毒的持续进化, 肯尼亚沿海地区,并建议需要对流行的季节性流感病毒进行持续的基因和抗原病毒监测,具有广泛的地理代表性,以方便及时有效地选择流感毒株纳入未来的流感疫苗。

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发表时间:2020-01-19
DOI:10.1093/cid/ciaa050
作者列表:["Baum U","Kulathinal S","Auranen K","Nohynek H"]

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影响因子:1.36
发表时间:2020-01-20
DOI:10.1111/1348-0421.12775
作者列表:["Ainai A","van Riet E","Ito R","Ikeda K","Senchi K","Suzuki T","Tamura SI","Asanuma H","Odagiri T","Tashiro M","Kurata T","Multihartina P","Setiawaty V","Andriana Pangesti KN","Hasegawa H"]

METHODS::Intranasally administered influenza vaccines could be more effective than injected vaccines, since intranasal vaccination can induce virus-specific IgA antibodies in the upper respiratory tract, which is the initial site of infection. In the current study, immune responses elicited by an intranasal inactivated H5 influenza vaccine were evaluated in healthy H5 influenza virus-naive individuals. Three doses of intranasal inactivated whole-virion H5 influenza vaccine induced strong neutralizing nasal IgA and serum IgG antibodies. In addition, a mucoadhesive excipient, carboxy-vinyl polymer (CVP), had a notable impact on the induction of nasal IgA antibody responses but not serum IgG antibody responses. The nasal hemagglutinin (HA)-specific IgA antibody responses clearly correlated with mucosal neutralizing antibody responses, indicating that measurement of nasal HA-specific IgA titers could be used as a surrogate for the mucosal antibody response. Furthermore, increased numbers of plasma cells and vaccine antigen-specific helper T (Th) cells in the peripheral blood were observed after vaccination, suggesting that peripheral blood biomarkers may also be used to evaluate the intranasal vaccine-induced immune response. However, peripheral blood immune cell responses correlated with neutralizing antibody titers in serum samples but not in nasal wash samples. Thus, analysis of the peripheral blood immune response could be a surrogate for the systemic immune response to intranasal vaccination but not for the mucosal immune response. The current study suggests the clinical potential of intranasal inactivated vaccines against H5 influenza viruses and highlights the need to develop novel means to evaluate intranasal vaccine-induced mucosal immune responses. This article is protected by copyright. All rights reserved.

影响因子:6.53
发表时间:2020-01-21
DOI:10.1016/S1473-3099(19)30584-5
作者列表:["Liebowitz D","Gottlieb K","Kolhatkar NS","Garg SJ","Asher JM","Nazareno J","Kim K","McIIwain DR","Tucker SN"]

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