Immunogenicity Of Recombinant CDV-adenovirus In Mink And The Construction Of Infectious Clone Of The Novel Vaccine

Canine distemper(CD) is an acute, febrile, highly contagious disease which is caused by canine distemper virus (CDV) causing considerable damages to the kennel industry and the fur animal farming industry; once the animals are infected, CDV will spread rapidly in the group, the mortality rate can reach30%-80%, resulting in huge economic lesses. Although many animals are immued annully, the epidemic still can not controlled, the main reason may be the evolutionary or genetic variation of the CDV itself, and the existing vaccines can not be effectively control CDV, so the study of the novel vaccine of Canine distemper virus is imminent.through the infected mink experiment, three strains of CDV isolated by different hosts and make virulence assessment. The results found that the virulence and pathogenicity of CDV from the Tibetan mastiff is strongest, which results in the deaths of the minks; and animal challenge experiments laid the foundation for CD vaccine assessment. Then the minks are immuned by two recombinant adenovirus vaccines which consist of adenovirus and CD hemagglutinin gene (H) or fusion protein gene (F). After the second immune, the half of minks are used for immune duration detetion experiments, and the other are maked for challenge protection experiments in the immuned mink using ZA-CDV. Discovering recombinant vaccines produce the CD antibodies in mink and little change in antibody titer in the three months, but compared with traditional attenuated vaccine, the immune effect of the recombinant vaccines is not too high; as for the chanllenged groups, the protection rate in CAVH group is highest, CDVFH group followed, CAVF is low; in addition, all of the control group are died.CD hemagglutinin gene (H) is a major antigen to stimulate the body to produce neutralizing antibodies, and plays a very important role in the anti-CDV immune process. In this study, in order to develop a more secured, effective and stimulate the body to produce a higher neutralizing antibody vaccine, FuDao CDV whose immunogenicity is better is used for carriers, full-length cDNA plasmid was constructed with inserted double H gene between P and M region and build the infectious clone for CD, and laiding the foundation for CD vaccine of better immunogenicity.