Onset of serum antibodies to Pasteurella (Mannheimia) haemolytica following vaccination with five commercial vaccines

Abstract

The purpose of this study was to compare the antibody responses of cattle vaccinated with one of five commercial non-living P. haemolytica vaccines during the first two weeks after a single vaccination. Antibodies to surface antigens (whole cells) and to the leukotoxin (LKT) were quantified at Days 7 and 14 after vaccination. In addition, antibodies to specific P. haemolytica whole cell protein antigens were determined by immunoblots using sera from vaccinated and control calves. Three hundred pre-weaned, mixed beef breed steers and heifers, greater than three months old, were equally divided among five vaccinated and one placebo groups. Cattle were subcutaneously injected with one of the following commercial P. haemolytica vaccines: One Shot, One Shot Ultra 8, Pyramid 4+Presponse SQ, Pulmo-guard PH-M or Poly-Bac B 1. Antibody responses to both LKT and whole cells were highest on Day 7 for One Shot and One Shot Ultra. By Day 14, Pulmo-Guard stimulated serum antibodies to both antigen preparations that were equivalent to those for One Shot and One Shot Ultra. Serum antibodies to LKT and whole cells were detected in the Pyramid/Presponse- and Poly-Bac 1 - vaccinated groups; however, those responses were not significantly different from the placebo group. Each vaccine, except for the Pyramid 4/Presponse - vaccinated group, stimulated antibodies to similar P. haemolytica somatic proteins, particularly at 200, 100, 60-70, 45, 35 and 25 kDa. Sera from the Pyramid 4/Presponse-vaccinated group recognized fewer protein bands, mainly those at 200, 70-75, 48 and 35 kDa. In conclusion, various commercial vaccines induced differences in the rapidity and the intensity of serum antibody responses to P. haemolytica whole cells and LKT.