Figure 1.

Mean ± SEM serum IgM titers in 22 BLV-positive cows (BLV POS) and 13 BLV-negative cows (BLV NEG) administered a J5 E. coli bacterin with 4 doses of bacterin administered SC in the left side of the neck (odd numbered doses) or right side of the neck (even numbered doses). Blood samples were collected from all cows at the time of the first (V1: approx 7 weeks before parturition), third (V3: second week after parturition (between days 8 and 14 after parturition)), fourth (V4: 5 weeks (between 29 and 35 days) after parturition) vaccinations, and 21 days after the fourth vaccination.