Field efficacy of combination vaccines against bovine respiratory pathogens in calves.
The efficacy of an inactivated bovine respiratory syncytial virus (BRSV)--bovine parainfluenza type 3 (PI3)--Mannheimia haemolytica (Mh) combination vaccine was examined in two field studies. Calves were vaccinated (i) with the inactivated vaccine, (ii) a modified live/killed viral combination vaccine, or (iii) left unvaccinated. The efficacy of the vaccines was judged by the (i) number of treated animals, (ii) number of individual antibiotic treatments per calf and (iii) mortality rates. After vaccination with the inactivated vaccine, the number of calves requiring antibiotic treatment was significantly lower than in the unvaccinated group (odds ratios: 0.26 first study and 0.53 second study), but differences between vaccination with live/killed combination vaccines and controls were not significant (odds ratios: 0.56 and 0.90, respectively). In both studies, a number of unvaccinated controls died due to respiratory disease (4.6% first and 6.7% second study). By contrast, none of the animals vaccinated with the inactivated vaccine died in the first study and only 3.3% in the second study. The mortality rates for the groups vaccinated with the live vaccine (1.3% and 7.8%) were similar to the unvaccinated controls. In summary, these data demonstrate the efficacy of the inactivated vaccine under field conditions.
Makoschey
Birgit
B
Intervet Schering-Plough Animal Health, Wim de Ki5rverstraat 35, NL-5831 AN, Boxmeer, The Netherlands. Birgit.Makoschey@sp.intervet.com
Bielsa
Juan Muñoz
JM
Oliviero
Loïc
L
Roy
Olivier
O
Pillet
Florence
F
Dufe
Divine
D
Valla
Giorgio
G
Cavirani
Sandro
S
D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001428:Bacterial Vaccines / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy / Q000517:prevention & control*; D016978:Mannheimia haemolytica; D048089:Pneumonia of Calves, Enzootic / Q000188:drug therapy / Q000517:prevention & control*; D018357:Respiratory Syncytial Virus Infections / Q000517:prevention & control*; D018112:Respiratory Syncytial Virus, Bovine; D017778:Vaccines, Combined / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*
D000900:Anti-Bacterial Agents; D001428:Bacterial Vaccines; D017778:Vaccines, Combined; D014765:Viral Vaccines