Efficacy of live vaccines against serologic subtypes of infectious bursal disease virus.
Experiments determined the efficacy of live vaccines in specific-pathogen-free broilers against serologic subtypes of infectious bursal disease virus (IBDV). Challenge isolates were the Delmarva variant E, a standard serotype I (APHIS) and a variant isolate from Mississippi. The vaccines were a cloned standard (CS) vaccine (Clone Vac-D78), a cloned variant (CV) vaccine (Bursa Vac IV), and an uncloned standard (UCS) vaccine (Bursine II). The severity of microscopic lesions was correlated with bursal atrophy as measured by bursa-weight-to-body-weight ratios. All vaccines provided adequate protection against the APHIS challenge. The three vaccines averaged 77% protection against APHIS in the first experiment and 78% in the second. Protection against the variant E and Miss isolates was considerably less for all vaccines. The three vaccines produced an average 70% protection against the Miss isolate in the first experiment and 69% in the second experiment. Against the variant E virus, the three vaccines averaged 67% protection in the first experiment and 65% in the second. There were significant differences in protection for each vaccine against individual IBDV subtypes. Results showed that no vaccine provided good protection (at least 80%) against all three subtypes of IBDV.
Giambrone
J J
JJ
Department of Poultry Science, Auburn University, Alabama 36849-5416.
Closser
J
J
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D002645:Chickens; D007243:Infectious bursal disease virus / Q000145:classification / Q000276:immunology*; D011201:Poultry Diseases / Q000517:prevention & control*; D012087:Reoviridae / Q000276:immunology*; D012088:Reoviridae Infections / Q000517:prevention & control / Q000662:veterinary*; D012703:Serotyping; D013047:Specific Pathogen-Free Organisms; D014765:Viral Vaccines / Q000276:immunology
D000914:Antibodies, Viral; D014765:Viral Vaccines