The construction and immunogenicity analyses of a recombinant pseudorabies virus with Senecavirus A VP3 protein co-expression

Senecavirus A (SVA)-associated porcine idiopathic vesicular disease (PIVD) and Pseudorabies (PR) are highly contagious swine disease that pose a significant threat to the global pig industry. In the absence of an effective commercial vaccine, outbreaks caused by SVA have occurred in many parts of the world. In this study, the PRV variant strain PRV-XJ was used as the parental strain to construct a recombinant PRV strain with the TK/gE/gI proteins deletion and the VP3 protein co-expression, named rPRV-XJ-Delta TK/gE/gI-VP3. The results revealed that PRV is a suitable viral live vector for VP3 protein expressing. As a vaccine, rPRV-XJ-Delta TK/gE/gI-VP3 is safe for mice, vaccination with it did not cause any clinical symptoms of PRV. Intranasal immunization with rPRV-XJ Delta TK/gE/gI-VP3 induced strong cellular immune response and high levels of specific antibody against VP3 and gB and neutralizing antibodies against both PRV and SVA in mice. It provided 100% protection to mice against the challenge of virulent strain PRV-XJ, and alleviated the pathological lesion of heart and liver tissue in SVA infected mice. rPRV-XJ-Delta TK/gE/gI-VP3 appears to be a promising vaccine candidate against PRV and SVA for the control of the PRV variant and SVA.