I. Hussain, M. H. Rasool and M. S. Mahmood

Department of Microbiology, University of Agriculture, Faisalabad, Pakistan

    The early and accurate diagnosis of infectious bursal disease requires known hyperimmune serum against the disease. In this study, an attempt was made to raise anti-infectious bursal disease virus hyperimmune serum in rabbits. The infectious bursal disease (IBD) virus was isolated from field outbreaks, identified, purified, titrated and its infectivity titre was determined in embryonated eggs. Three different semi purified and purified doses were prepared for inoculation in rabbits: (i) chloroform treated IBD virus; (ii) ultra centrifuged and resuspended virus using sucrose as gradients and (iii) pelleted and resuspended virus with addition of incomplete Freund's adjuvant. Killed IBD virus vaccine (Cevac IBDK) was used as 4^th inoculum. It was observed that the serum collected after series of inoculation of 1st and 2nd inoculum provided maximum antibody titre upto log₂6 and Log₂9, respectively. However, the serum collected after series of injection of 3^rd and 4^th inoculum gave maximum indirect haemagglutination (IHA) titer (log₂10). This study suggested that live antigen containing incomplete Freund's adjuvant provided better immune response and may be a good choice for raising a hyperimmune serum against IBD virus in rabbits.

Key words: Hyperimmune serum, infectious bursal disease, incomplete Freund's adjuvant, rabbits