Evaluation of the efficacy of a candidate turkey cellulitis/dermatitis oil emulsion vaccine on immune response and mortality under laboratory and commercial conditions

Abstract

SUMMARY: Ability of a Clostridium septicum (CS) bacterin-toxoid, in conjunction with adjuvants such as aluminum hydroxide, mannoslyated chitosan, or a water-in-oil emulsion Seppic Montanide 71 R VG adjuvant (OE) to induce immunity was evaluated in a 7-wk study (Experiment 1). Poults (20/group) were vaccinated on day of hatch, boosted at 5 wk of age and compared to unvaccinated controls. In Experiment 1, initial vaccination with OE resulted in significantly (P < 0.05) higher antibody levels at 5 wk of age, and at 7 wk of age OE resulted in numerically increased antibody levels compared to all vaccinated groups. OE vaccine efficacy was evaluated in 2 field trials (Experiments 2 and 3) with treatments including a non-vaccinated control group and a vaccinated group. Experiment 2 consisted of 3 houses. Blood samples were obtained at time of field vaccination, 4 wk post-vaccination, and processing. Antibody levels (S/P ratio) in vaccinated groups for weeks 12 and 16 were significantly higher (P < 0.05) than control groups for all houses. Experiment 3 consisted of 6 farms with 1–4 houses/farm. Vaccination significantly (P < 0.05) reduced CS-related mortalities as compared to controls in 5 of 6 farms and antibody titers were significantly (P < 0.05) higher in vaccinated turkeys from 4 wk post-vaccination through processing, for all 6 farms. Based on these results, OE vaccines can be used to increase antibody titers and may reduce CS-related mortalities in the field.

Keywords

• oil-emulsion vaccine
• turkey cellulitis
• Clostridium septicum
• alpha-toxin
• antibody titer