Protection induced by a recombinant replication-defective adenovirus vaccine expressing the P97 protein o￡ Mycoplasma byopneumoniae in challenged pigs: Comparison to Suvaxyn~R MH-one vaccine

摘要

Mycoplasma hyopneumoniae is the causative agent of en-zootic pneumonia in pigs, a chronic respiratory disease that causes major economic losses to the pig industry worldwide. The disease is characterized by chronic nonproductive cough, retarded growthrate, and inefficient food conversion. Vaccination against M hyopneumoniae is an important prophylactic approach used to control mycoplasma pneumonia in pigs. The commonly used vaccines consist of inactivated whole cells, such as Suvaxyn MH-one. Although numerous studies report that these vaccines are protective against experimental challenge, vaccination failure in production settings is also documented.1 Adherence to epithelial cells of the respiratory tract of swine is crucial in the pathogenesisof M hyopneumoniae and the surface protein called P97, particularly its C-terminal portion, is implicated. Therefore, this protein could represent an attractive target to develop effective vaccines against M hyopneumoniae. Replication-defective recombinant adenovirus-es (rAd) are extensively used as antigen delivery vehicles vectors and are known to induce both humoral and cellular protective immune responses against several diseases. In addition, as live vectors; rAd can be administered by mucosal route to stimulate the mucosal immunity. The objective of this study was to compare the vaccination efficiency of a subunit vaccine based on rAd expressing the C-terminal portion of P97 adhesin of M hyopneumoniae and the commercial vaccine (Suvaxyn~R MH-one)following experimental infection of pigs with M hyopneumoniae.