Comparative assessment of immunogenicity of commercial Newcastle disease vaccines available in Nigeria

Abstract

Newcastle disease (ND) is a major disease of poultry worldwide with significant economic importance and its major means of control is vaccination. However, there have been reports of recurring outbreaks in vaccinated flocks in Nigeria with various reasons adduced, including vaccine failure, particularly, of the imported varieties of vaccines. This therefore necessitated the assay of the immunogenicity of some commercially available ND-LaSota (ND-L) vaccines in Nigeria. Seven available brands of ND-L vaccines and 100 day-old broiler chicks of Arbor-Acres breed were used for the study. The broiler chicks were divided into 8 groups namely, A, B, C, D, E, F, G and H of 10-15 birds per group. A brand of vaccine was administered in drinking water at 7 and 30 days of age per group, while group H received no vaccine. All vaccines were imported except that of group F which was locally produced. Each vaccinated group was bled at 14, 21, 28, 44 and 51 days of age, serum samples were harvested and subjected to haemagglutination inhibition test for the detection of ND antibody titers. Data were analysed using analysis of variance and Duncan’s multiple range test. At 21, 28, 44 and 51 days of age, mean geometric titers (MGT) in Group F were 3.85 log₂, 5.25 log₂, 4.2 log₂ and 5.75 log₂, respectively, while the other groups had MGT ranges of 0.90 log₂ (H)-3.10 log₂ (G), 0.75 log₂ (H)–4.5 log₂ (G), 0.46 log₂ (H) – 4.9 log₂ (C) and 0.27 log₂ (H)–4.91 log₂ (G), respectively. Modal titres at these ages were 4, 8, 2 and 4, respectively, in Group B; 16, 32, 16 and 32, respectively in Group F; as well as, 2, 0, 0 and 0, respectively, in Group H. This study has shown that the locally produced ND-LaSota strain vaccine is more immunogenic than the imported brands.