Comparative Efficacy in Challenge Dose Models of a Toxin Expressing Whole-Cell Vaccine against Eight Serovars of Actinobacillus pleuropneumoniae in Pigs

Abstract

Actinobacillus pleuropneumoniae is a major economically significant bacterial respiratory pig pathogen, and whole cell vaccines are used to prevent disease. However, there is little data available on multi-serovar whole cell vaccine protection. Therefore, we determined the protective efficacies of a whole-cell A. pleuropneumoniae serovar 1 and 2 vaccine comprising ApxI-III toxins (C-vaccine, Coglapix®, Ceva, France) against serovars 1, 2, 4, 5, 6, 7, 9/11 and 13. The infection doses used induced disease representative of endemic field conditions, and standard protocols were used for all studies. Protection against homologous serovars 1 and 2 significantly reduced lung lesion scores (LLS) compared to positive controls: p = 0.00007 and p = 0.00124, respectively. The protection against heterologous serovars 4, 5, 6, 7, 9/11, and 13 also significantly reduced LLS: range p = 2.9 × 10−10 to p = 0.00953. As adjudged by the estimated random effect, reproducibility between studies was high. A highly significant serovar-independent reduction of pathological lung lesions by the C-vaccine was found for all the serovars tested (1, 2, 4, 5, 6, 7, 9/11 and 13). We conclude that the C-vaccine gives high serovar-independent protection against disease and is suitable for this use in the field.

Examination of the Virulence of Actinobacillus pleuropneumoniae Serovar 16 in Pigs

“…Several infection models have been used. Pigs were infected with A. pleuropneumoniae by intratracheal [ 9 , 28 ] intranasal [ 29 , 30 , 31 ], intradermal or subcutaneous [ 32 ], and aerosol [ 33 , 34 ] ways. Mouse infection assays were also described using intranasal [ 35 ] and intraperitoneal challenge [ 36 ].…”