Studies On The Immuno-interference Of Divalent Vaccine Of Classical Swine Fever And Pseudorabies

Classical Swine Fever (CSF) and pseudorabies (PR) are main epidemic diseases which greatly influence the healthy development of large-scale hog industry. In order to decrease the stress reaction from repeated immune inoculation, reduce the cost of vaccine and control the epidemic prevalence of two kinds of diseases, studies on the development of an economical, convenient and high immune efficacy divalent vaccine for CSF and PR is urgent and essential.The experiment was divided into three parts.First of all, pigs inoculated by the divalent vaccine for CSF and PR and their immune efficacy were inspected after inoculation. The result shows that, while immunization of divalent vaccine is performed, PR can interfere with the pre-antibodies of CSF. The antibody of CSF can be detected after 3 weeks inoculation, however, the antibody of PR can be tested for only 7d. The amount of two kinds of antibodies are in peak after 49d, and their corresponding peak values are slightly lower than those of single or hourly immunization, respectively. Also, it turns out that antibodies of hourly and split inoculation are lower than those of single inoculation, but interference between them were not obvious.Then the transfer factor to strengthen the immune effect of CSF vaccine was observed. The result shows that compared with control group, each group of transfer factor inoculation has a higher positive rate. In the low dose group of transfer factor, its immune effect is different from the control group at 7d after inoculation. In the median dose group, the result turns out to be significantly different at 7d. However, the high dose group is similar to the medium dose group. The immune effect for inoculating transfer factor at 7d is superior to those of at 14d and 21d. It suggests that when CSF vaccine is inoculated, transfer factor can be used to lower the immune response, reduce immune injury and raise the level of antibodies. Thus, injected transfer factor in the dose of 2mL per head and CSF vaccine in dose of 1 copy per head, simultaneously, is recommended.Finally, transfer factor used to strengthen the immune effect of divalent vaccine was inspected. The result shows that the immune effect is optimal at 7d if transfer factors are utilized as immune enhancement agents and the average level of antibody turns out to be positive at 21d, which suggests that if the transfer factors are inoculated as immune enhancement agents of divalent vaccine, it can effectively lower PR's interference to CSF and shorten the period that can detect a positive result. Concurrently, transfer factor can raise the positive rate of CSF which infered that it can significantly improve the immune effect of CSF. In addition, the transfer factor also has immune inhancement effect. The experiments shows that the divalent vaccine of classical swine fever and pseudorabies have immune interference, which means that the pre-antibodies of PR can interfere with the production of CSF antibody, which leads to CSF's late positive result after 3 weeks (28d). The transfer factor can both significantly strengthen the single CSF and divalent vaccine's immune effect and the antibody produced by CSF vaccine can be detected a positive result at 2 weeks. It suggests that the transfer factor can lower the immune interference between PR and CSF.