ABSTRACT
<p><b>OBJECTIVE</b>To under stand influenza A viruses epidemic, antigenicity and genetic characteristics variation between the vaccine and Circulation strains during 2004-2008 year in China.</p><p><b>METHODS</b>The influenza A viruses (H1N1, H3N2) isolated from 2004-2008 year were under took antigenic and sequence analysis. Influenza A virus antigenicity and genetic characteristics were analyzed thought amino acid variation compassion of HA1 protein of influenza A virus isolates.</p><p><b>RESULTS</b>The antigenicity of influenza H1N1 subtype viruses isolated from 2004 to 2007 is very similar with vaccine strain A/New Caledonia/20/1999 (HIN1)-like virus. The influenza H1N1 viruses circulated in 2008 year had similar antigenic characteristics with A/Brisben/59/2007 (H1N1) which is component of influenza vaccines for northern hemisphere 2008-2009 year. The influenza H3N2 subtype viruses of 2004-2005 year had antigenic variation comparatively with vaccine strain A/Fujian/411/12002 (H3N2), The antigenicity of 2006-2007 H3N2 viruses and 2008 year's is A/Wiscansin/67/2006(H3N2) and A/ Brisben/10/2006(H3N2) respectively.</p><p><b>CONCLUSION</b>There is change of influenza A viruses (H1N1, H3N2) antigenic and genetic characteristics during 2004-2008 in China.</p>
Subject(s)
Animals , Dogs , Humans , Amino Acid Sequence , Antigenic Variation , Cell Line , China , Epidemiology , Hemagglutinin Glycoproteins, Influenza Virus , Chemistry , Genetics , Allergy and Immunology , Influenza A Virus, H1N1 Subtype , Chemistry , Classification , Genetics , Allergy and Immunology , Influenza A Virus, H3N2 Subtype , Chemistry , Classification , Genetics , Allergy and Immunology , Influenza, Human , Epidemiology , Virology , Molecular Sequence Data , Phylogeny , Sequence AlignmentABSTRACT
A new flu caused by a novel influenza A(H1N1) virus has spread over the United States, Mexico and more than 40 other countries. And because of the immediate global concern, WHO has announced that the current level of influenza pandemic alert is raised to phase 5, indicating approaching of an influenza pandemic. As patients suffering from the influenza A (H1N1) have the similar symptoms as patients with seasonal influenza, differential detection and identification of the influenza virus have to depend on specific laboratory tests. We have successfully developed a RT-PCR based method for detection of the influenza A (H1N1) virus, and had applied the method to detection of clinical samples.
Subject(s)
Humans , Influenza A Virus, H1N1 Subtype , Genetics , Influenza, Human , Virology , RNA, Viral , Genetics , Reverse Transcriptase Polymerase Chain Reaction , MethodsABSTRACT
<p><b>OBJECTIVE</b>To analyse seasonal influenza epidemic situation in 2006, and to analyse the genetic and antigenic characteristics of viral hemagglutinin (HA) gene.</p><p><b>METHODS</b>The single-way hemagglutination inhibition (HI) tests were used to test the antigenic characteristics of these viruses from influenza surveillance network, and the HA1 genes were sequenced based on the antigenic test results according to different isolation times and sites.</p><p><b>RESULTS</b>The influenza virus types A and B co-circulated in 2006. influenza A H1N1 subtype and Victoria-like B influenza circulated preponderantly during this epidemic season. The HA1 gene sequence of H1N1 viruses showed that 192, 193, 196, 198 positions (located at antigenic site B) have an amino acid substitute, compared with the last circulating strain A/Hubeihongshan/53/2005(H1N1). Two amino acid changes at 142 and 144 positions compared with A/Yunnan/1145/2005 (H3N2). There was no change in influenza B viruses either Victoria-like B or Yamagata-like B virus, i.e . antigenic characteristics is analogous to B/shenzhen/155/2005 and B/tianjin/144/2005, respectively.</p><p><b>CONCLUSION</b>The H1N1 and H3N2 influenza viruses had changing antigenic and genetic characteristics in 2006. Influenza virus types B did not change in 2006.</p>