Comparative immunogenicity of local and imported infectious bursal disease (IBD) vaccines administered to chicks at different days of age

Abstract

A comparative immunogenicity and efficacy study of local and imported infectious bursal disease (IBD) vaccines administered to chicks (cockerels) at varying regimes (10 and 18, 10 and 28, 14 and 35 days of age) was carried out. The test birds were challenged seven days after the booster dose of the IBD vaccine by administering six drops of 20% suspension of infected Bursa of Fabricius homogenate in saline intraocularly. The results showed that the control (unvaccinated) birds as well as those that were vaccinated on the 14 and 35" days of life showed signs of IBD and up to 80% of the birds in these two categories died two days post-challenge. The birds that were vaccinated on the 10% and 18and 10and 28 days of life were apparently protected from clinical infection as there was no morbidity or mortality among them as a result of the IBD virus challenge. The results of the study suggest that both local and imported vaccines are immunogenic and vaccination of chicks on the 10h and 184 and 10h and 28 days of life is effective and protective.