Protection afforded infectious bronchitis virus-vaccinated sentinel chickens raised in a commercial environment.
The protective efficacy of three infectious bronchitis virus (IBV) vaccines for sentinel chickens raised with commercial Delmarva broiler chickens was evaluated during winter 1987. Specific-pathogen-free leghorn sentinel chickens were vaccinated with Massachusetts (Mass) alone, Mass and JMK, or Mass and Arkansas (Ark) combination live vaccines, or they remained unvaccinated. Four weeks post-vaccination, sentinels were placed on broiler farms at weekly intervals for 3 weeks corresponding to weeks 4, 5, and 6 of the broiler growing cycle. Vaccine efficacy was evaluated based on IBV reisolation attempts from tracheal swabbings following a 1-week field exposure period. Sentinel chickens vaccinated with Mass and Ark combination vaccine were best protected against IBV field challenge. Only four IBV isolations were made out of a 3-week total of 36 attempts, for an 11% isolation rate. IBV vaccines containing either Mass alone or Mass and JMK offered much lower levels of protection.
Gelb
J
J
Department of Animal Science and Agricultural Biochemistry, College of Agricultural Sciences, University of Delaware, Newark 19717-1303.
Rosenberger
J K
JK
Fries
P A
PA
Cloud
S S
SS
Odor
E M
EM
Dohms
J E
JE
Jaeger
J S
JS
D000822:Animal Husbandry; D000818:Animals; D000956:Antigens, Viral / Q000032:analysis*; D002645:Chickens / Q000276:immunology*; D003332:Coronaviridae / Q000472:pathogenicity*; D001351:Infectious bronchitis virus / Q000276:immunology / Q000472:pathogenicity*; D013047:Specific Pathogen-Free Organisms; D014611:Vaccination / Q000662:veterinary; D014765:Viral Vaccines / Q000627:therapeutic use*
D000956:Antigens, Viral; D014765:Viral Vaccines