Comparative study on locally produced bivalent inactivated Newcastle disease vaccine in broiler chicks

Abstract

The study included titration of the Newcastle disease virus strains before preparation of the vaccines used in this experiment, by detection of EID50 for these strains. This study regarded the first one in the country in the preparation double strain oily Newcastle disease virus vaccine. The immune responses for this vaccine were compared with those of single strain NDV vaccine. The same vaccination program was used for all groups included in this study in which live attenuated )Lasota strain) vaccine given at one day old as an installation by eye and nostril, and subcutaneous injection of oily vaccine at the neck region. A total of 120 commercial broiler chicks was divided into fourth groups (1 )group vaccinated with live attenuated vaccine and bivalent (B1, Lasota ) oily vaccine while the (2)group vaccinated with live attenuated vaccine and (Lasota) oily vaccine and (3) group vaccinated with live attenuated vaccine and (AG68) oily vaccine, (4) group C was left unvaccinated as control, the Immune response for all groups was measured at ( 1) day old, (7), (14), (21), and ( 35) days old by heamagglutination test (HI) and Enzyme linked immunosorbent assay (ELISA). The results showed gradual recreation of immune response titer at 7, 14 and 21 days post vaccination intervals with non-significant differences (P> 0.05) among vaccinated groups at (7, 14) days and significant difference between vaccinated groups and control group (P>0.05) at (21) days old. The third group reflected better titer among vaccinated groups, and the result shows increased antibodies titer at (35) day in comparison with antibodies titer at (14, 21) days intervals. With statistical differences (P>0.01) among (third) group and second, and control group). However all groups gave higher titer than the control group (P>0.01) and the result of (HI) test agreement with (ELISA) test while the protection percentage were measured by challenge test, it was found to be ( 100 % ) for group (3) vaccinated with live attenuated vaccine and bivalent (B1, Lasota) oily vaccine, (92%) for the second groups (2) (96%) for the first groups (1) whereas the control group (4) gave (10%) protection. This study indicates efficacy of prepared ND vaccines (B1, Lasota) as compared with monoclonal vaccines (B1, Lasota) and the high immunosuppressive capacity of the oily vaccine increased with virulence.