Observations on Immune Effects of Inactivated Bivalent Foot-and-Mouth Disease Vaccines on Adult Sheep in Xinjiang

JIAN Zi-jian1,MA Su-zhen1,Lü Chun-hua2(1.College of Veterinary Medicine,Xinjiang Agricultural University,Urumqi 830052;2.Center of Animal Disease Control and Diagnosis,Altay Prefecture,Altay 836500)

adult sheep;inactivated bivalent foot-and-mouth disease vaccines;immune responses;immune monitoring;ELISA antibody

Even though sheep infected with foot-and-mouth disease virus(FMDV) usually show less clinical evidence than cattle and pigs,it can not underestimate their epidemiological role in the spread of foot-and-mouth disease(FMD).In this study,previously vaccinated adult sheep in a six moth interval were selected and revaccinated with three kinds of inactivated bivalent foot-and-mouth disease vaccines for the examination of their immune efficiency,and the tracking immune monitoring was performed simultaneously.The results were shown that titers of ELISA antibodies against FMDV sorotypes O and Asia-Ⅰ in all sheep screened were increased above lg2.19 at 30 days postvaccination(dpv).The titers reached the peak values after 30dpv,60dpv and 90 dpv,respectively,and then decreased mildly.The ELISA antibody titers were sill maintained between lg1.86 and lg2.20 by end of the experiment(150 dpv).The qualification rates of ELISA antibodies to sorotypes O and Asia-Ⅰ for the three kinds of inactivated bivalent foot-and-mouth disease vaccines were ≥70% and ≥80%,respectively,and were identified with the national standards.The results also suggest that it is feasible for vaccinated adult sheep in a six moth interval to revaccinate the inactivated bivalent foot-and-mouth disease vaccines two times per year.