| Classical swine fever (CSF), also known as European swine fever or hog cholera，isa kind of highly pathogenic, high mortality and contagious multisystemic hemorrhagicviral disease of pigs. Classical swine fever virus (CSFV) is its etiological agent, andthe only natural hosts are domestic pigs and wild boars.In history, there were manylarge outbreaks of CSF. Everytime, the outbreak will cause an enormous economicloss, and impair internal and international trade of pigs and pig products. The situationof CSF epidemic is still severe, and CSF is classified as a list A disease by the WorldOrganization for Animal Health (OIE).The classical swine fevervirus (CSFV), is a member of the Pestivirus genus ofFlaviviridae family. CSFV is a small (40–60nm in diameter) envelopedpositive-stranded RNA virus, with a12.3kbgenome. Its genome possesses anon-capped5’untranslated region (5’UTR), a single large open reading frame (ORF),and a3’untranslated region (3’UTR).CSFV has four structural proteins: nucleocapsidprotein C, envelope glycoproteins E0, E1and E2, and eight nonstructuralproteins:Npro, p7, NS2, NS3,NS4A, NS4B, NS5A and NS5B.At present, in China, the CSFV vaccine used to prevent CSF is "54III lapinizedvirus" selected in1954, also known as Chinese vaccine strain(C-strain) or hog choleralapinized virus (HCLV). C strain retains advantages of strong immunity, lastingeffects, genetic properties of stability and no residual toxicity, and is recognizedinternationally as the best attenuated vaccines，therefore, has been widely used in theworld, and played an important role in controlling CSF epidemic in domestic pigs.Italso has a wide future to use as a vaccines vector.Influenza virus belongs to Orthomyxoviridae which is classified into three types ofA,B,C. Influenza A virus (IVA) is the etiological agent of Influenza. Usually, IVA results in significant illness, a large number of deaths, disruption of social life andeconomic losses. In past century, the world had experienced three pandemics: the1918Spanish influenza caused by H1N1virus, the1957Asian influenza caused byH2N2virus, and the1968Hong Kong influenza caused by H3N2virus.In this century,a novel H1N1virus of swine origin was detected in humans in early April of2009andquickly became pandemic in June2009(now called ‘pandemic (H1N1)2009’) as aresult of highly efficient transmission in humans.At present, the whole world pandemic H1N1influenza is threatening the health ofhuman. The pathogen analysis found that the virus and swine influenza viruses havethe highest nucleic acid sequence homology, suggesting its origin from theswineinfluenza virus.When we put a lot of manpower and material resources toprevent and control of H1N1IVA epidemic in human, it is necessary to consider theproblem how to effectivelycut off the flu virus transmission from pigs to human onthe level of its origin.For viral diseases, the most effective measures to prevent and control H1N1influenza are preventive inoculation with effective vaccine. However，There is noformal vaccine available to prevent the H1N1influenza A virusat present. Therefore,it becomes necessary to research and develop H1N1IVA vaccine to control influenzavirus spread in pigs.In our study, we use the infectious cDNA of C-strain constructed in our laboratorypreviously and HA genes of H1N1obtained from the cooperative lab to construct aH1N1IVA-classical swine fever bivalent live vector vaccine in order to not onlycarry out the planned immunization for classical swine fever,but also prevent andcontrol the swine influenza virus spread among pigs. Thus,it might cut off the route ofinfection that the H1N1IVA spread from pigs to human in the origin. As a result, itwill lay the foundation for the prevention and control of IVA. At the same time, wealso create a good lab method to detect the classical swine fever virus in pk-15cells,which has a highly sensitivity and accuracy rate. At the same time, the detectionmethod can also be used to test the vector based on the C-strain cDNA. |
