1. To address this question, the breadth and magnitude of the antibody response to all regions of Msp2 were compared PD0325901 chemical structure in immunized animals and non-immunized, infected animals at the time of control of the initial bacteremia. Regardless of the treatment, the breadth scores to the HVR peptides were higher than the CR peptides (Fig. 2a). For example, the immunized animals had a mean breadth score of 0.19 ± 0.12 for the CR peptides and a score of 0.67 ± 0.15 for the HVR peptides; while the infected animals had a breadth

score of 0.15 ± 0.06 for the CR peptides and 0.71 ± 0.14 for the HVR peptides. The breadth scores to the CR peptides were slightly higher in the immunized animals (0.19 ± 0.12) than in the infected animals (0.15 ± 0.06). However, these differences were not statistically significant and are unlikely to be biologically relevant, as they predominantly represent differences between individual animals, and are due to the recognition of three additional CR peptides, P3, P15, and P14. P3 and P15 were recognized by vaccinee 5933. Although this animal had the highest breadth score (0.40) for the CR peptides, it also had the second highest bacteremia (4.5% infected erythrocytes) of the immunized animals

(Table 3). P14 was solely recognized by vaccinee 5952. The breadth scores RG7420 nmr to the HVR peptides were similar when comparing the immunized and infected animals, with the scores in the infected animals marginally higher (Fig. 2a). When comparing titers, the immunized animals had higher titers to the CR of Msp2 than did the infected animals (Fig. 2b). However, the difference was not statistically significant and was attributed to the variation among individual Astemizole animals. The infected cattle had higher titers to the HVR than did the vaccinees, however, this was primarily attributed an animal (5967) with markedly high titers. Similarly, there were no significant differences between the immunized and infected animals when evaluating the titers to individual peptides (Supplemental Fig. 1). Due to the wide variation among individuals within a group, we posed the following question: within a treatment group, is there a correlation

between the control of bacteremia and the breadth or magnitude of the anti-Msp2 antibody response? Among the animals that were infected, there was no correlation between the breadth scores to either the CR or HVR peptides and bacteremia (Fig. 3). For example, one of the animals (5969) with the highest total breadth (including both the HVR and CR) score also had the highest bacteremia (31%). In contrast, there was a strong inverse correlation between bacteremia and titers to the CR (Fig. 4a), but not the HVR (Fig. 4b), of Msp2. Those animals with higher titers to the CR had lower levels of bacteremia (Spearman rank correlation coefficient = −0.97, p ≤ 0.005). To address this question, only the immunized animals were considered.