Evaluating the Protective Efficacy of a Live and Two Killed Vaccines against Infectious Bursal Disease in Commercial Chicks in Zaria, Nigeria

This study evaluated and compared the efficacy of a live (intermediate plus strain) and two killed (produced from intermediate plus and intermediate strains of viruses) infectious bursal disease vaccines in commercial Isa brown cockerel chicks. Two hundred and eighty, one day old chicks were divided into four groups of seventy chicks each. Group 1, 2 and 3 were vaccinated with live vaccine, killed vaccine A (produced from intermediate plus strain) and killed vaccine B (produced from intermediate strain) respectively while group 4 was not vaccinated. Vaccination was conducted at 9 and 16 days of age with group 1 vaccinated orally and groups 2 and 3 vaccinated intramuscularly via the leg muscles. Blood was collected from 15 chicks in each group weekly from 2 to 44 days of age. Twenty chicks from each group were challenged with a very virulent infectious bursal disease virus (vvIBDV) at 30 days of age. Agar gel precipitation test (AGPT) performed on the sera revealed that the group vaccinated with live vaccine had the highest percentage of chicks with antibody at all ages followed by group 2 (killed vaccine A). Precipitin antibodies were not detected in chicks in groups 3 (killed vaccine B) and 4 (unvaccinated) at all ages. Enzyme-linked immunosorbent assay (ELISA) performed on the same set of sera revealed that Angani M T 1* , Abdu P A 2 and Sa'idu L 3