Studies On Inactivatded Oil-Emulsion Vaccine Against Avian Infectious Laryngotracheitis

This research compared two strains of infectious laryngotracheitis virus (ILTV),ILTV-wanggang strain and ILTVNM98a strain,based on the culture on the kidney cells of chicken embryo and in embryonating chicken eggs.As far as the same strain was concerned,the content of the viruses growing in embryonating chicken eggs was more than or as much as on the kidney cells.the virus content of ILTV~NM9ga strain cultured in embryonating eggs was a little more than that of ILTV-wanggang strain.In the experiment of inactivating virus,both formaling and biethyleneimine(BEI) could inactivate ILTV very well.but after chicken were vaccined by the formaling inactivated vaccine,both their serum antibody titer and their protection against virulent ILTV were less than that vaccined by the BEI inactivated vaccine.When compared with live attenuated vaccine,the formaling inactivated vaccine and the BEI inactivated vaccine could induct higher serum antibody titer but produce less protective ratio.Protective ratio of live attenuated vaccine was 76.7%,the BEI inactivated vaccine was 73.3% and formaling inactivated vaccine was 53.3%.