Immunity Evaluation of Inactivated Newcastle Disease Virus Vaccine Inoculated at Different Doses in Day-old Specific-Pathogen-Free Chicks

This research aims to evaluate the immunogenicity of different doses of HIPRAVIAR® BPL2 inactivated Newcastle disease virus (NDV) LaSota vaccine. Specific-pathogen-free day-old chicks were divided into 3 different groups, and each group was vaccinated subcutaneously with the vaccine dose of 0.1, 0.2, and 0.5 ml, respectively. Blood samples were collected to measure NDV-specific antibody titers using a hemagglutination inhibition (HI) test and enzyme-linked immunosorbent assay (ELISA). The HI result showed that birds vaccinated with 0.5 ml HIPRAVIAR® BPL2 vaccine showed an increased statistically significant antibody titer compared to the other doses. Similarly, the ELISA result corroborated the HI finding. No significant difference between the results was detected when the antibody titers were measured using two ELISA kits, Biocheck CK116, and CIVTEST® AVI NDV. The percentage antibody-positive test based on HI amongst the different days post-vaccination showed that all the birds were positive from 28 to 42 days following vaccination with HIPRAVIAR® BPL2 0.5 ml (group D), whereas the highest percentage of antibody positivity were 80% and 70% at 42 days post-vaccination with HIPRAVIAR® BPL2 0.1 ml (group B) and HIPRAVIAR® BPL2 0.2 ml (group C), respectively. In conclusion, besides the difference in seroconversion, all the vaccine doses used had important levels of seroconversion and positivity.