Departamento de Medicina Preventiva Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, 8820808, Chile.
Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, 55108, USA.
Sci Rep. 2020 Mar 11;10(1):4510. doi: 10.1038/s41598-020-61315-5.
Novel H1N2 influenza A viruses (IAVs) in swine have been identified in Chile co-circulating with pandemic H1N1 2009-like (A(H1N1)pdm09-like) viruses. The objective of this study was to characterize antigenically the swine H1 IAVs circulating in Chile. Genetic analysis based on the HA1 domain and antigenic analysis by hemagglutination inhibition assay were carried out. Three antigenic clusters were identified, named Chilean H1 A (ChH1A), Chilean H1 B (ChH1B), and A(H1N1)pdm09-like. The antigenic sites of ChH1A and ChH1B strains were 10-60% distant from those of commercial vaccine strains at the amino acid sequence level. Antigenic variants were identified within the clusters ChH1A and A(H1N1)pdm09-like. Substitutions in the main antigenic sites (E153G in Sa, Q193H in Sb, D168N in Ca1, P137S in Ca2, and F71L in Cb) were detected in variants from the ChH1A cluster, whereas only a single substitution in antigenic site Sa (G155E) was detected in variants from A(H1N1)pdm09-like cluster, which confirms the importance to carrying out antigenic analyses in addition to genetic analyses to evaluate control measures such as vaccination. These results highlight the need to update vaccines for swine in Chile and the importance of continued surveillance to determine the onward transmission of antigenic variants in Chilean pig populations.
在智利，与大流行 H1N1 2009 样（A（H1N1）pdm09 样）病毒共同流行的猪中已鉴定出新型 H1N2 甲型流感病毒（IAV）。本研究的目的是对在智利流行的猪 H1 IAV 进行抗原特征分析。基于 HA1 结构域进行遗传分析，并通过血凝抑制试验进行抗原分析。确定了三个抗原簇，分别命名为智利 H1 A（ChH1A）、智利 H1 B（ChH1B）和 A（H1N1）pdm09 样。ChH1A 和 ChH1B 株的抗原位点在氨基酸序列水平上与商业疫苗株的距离为 10-60%。在 ChH1A 和 A（H1N1）pdm09 样簇内鉴定出抗原变体。在 ChH1A 簇内的变体中检测到主要抗原位点（Sa 中的 E153G、Sb 中的 Q193H、Ca1 中的 D168N、Ca2 中的 P137S 和 Cb 中的 F71L）中的取代，而在 A（H1N1）pdm09 样簇内的变体中仅检测到抗原位点 Sa 中的单个取代（G155E），这证实了除了遗传分析之外，进行抗原分析以评估控制措施（如疫苗接种）的重要性。这些结果强调了需要更新智利猪用疫苗，并需要继续监测以确定抗原变体在智利猪群中的传播情况。
