Studies On Synchronized Immunization Method With Classical Swine Fever And Foot-and-mouth Disease Vaccines

Classical swine fever (CSF) is a highly contagious viral disease, which is caused byclassical swine fever virus (CSFV). Foot-and-mouth disease (FMD), is an acute, violentand highly contagious zoonosis, which is caused by the foot-and-mouth diseasevirus(FMDV) in cloven-hoofed animals. They were both enlisted as numbers on the ListA of contagious diseases by OIE and on the List I of animal diseases in our country. Atpresent, there is still no effective drug for the treatment of CSF and FMD, so vaccines areeffective method to prevent them and they have been listed as compulsory vaccinationprojects in our country. But for compulsory immunization of CSF and FMD in the past,the step-by-step immunization method was used, for which two vaccines were injectedwith an interval of 7-10d, respectively. This method have some disadvantages, such aslong immunization period, high cost, time-consuming, labor, and uncertain vaccinationdensity and prevention effect.In this study, the immune responses of synchronized and step-by-step immunizationof CSF and FMD vaccines were observed. The results showed that the side effect rate was23.3ï¼…for the synchronized immunization and 21ï¼…for the step-by-step immunization.The difference was not significant.For the synchronized immunization of CSF and FMD vaccines, the avergequalification rates of antibodies were 38ï¼…, 78ï¼…, 85ï¼…, 45ï¼…, 32ï¼…and 25ï¼…, and those forstep-by-step immunization of CSF and FMD vaccines were 38ï¼…, 80ï¼…, 84ï¼…, 41ï¼…, 30ï¼…and 23ï¼…at 10d, 20d, 30d, 40d, 50d and 60d after immunization, respectively. Theimmune efficacy was similar for two immunization methods. The effective protectiontime was an about 30d after immunization. And the results showed there was notobviously mutual interference between CSF and FMD vaccines for the synchronizedimmunization.At 30d after synchronized immunization of CSF and FMD vaccines, a strengthenedimmunization was performed. The results showed that the averge qualification rates ofantibodies were 81ï¼…, 86ï¼…, 81ï¼…, 69ï¼…and 47ï¼…at 30d, 60d, 90d, 120d and 150d after thefirst immunization, respectively. The antibody could keep longer time after the secondimmunization, and the effective protection period was more than 90d after the firstimmunization. The second immunization had a strengthened effect on the first one. Theeffect of synchronized immunization twice was better than that of once.For synchronized immunization and strengthened immunization, the immune effectsof different immune doses were compared. Double doses/pig for CSF vaccine and one dose/pig for FMD vaccine on both of the first and second immunization, showed the bestvaccination effect.In the study, some experiments about immune side effects, immune effects,strengthened immunization and immune doses for synchronized immunization ofvaccines were finished. Our data is useful to develop the combined immunizationresearches of CSF and FMD with other vaccines in the future.