A Combination Vaccine against Encephalomyocarditis Virus and Porcine Circovirus Type 2 Induces Protective Immune Response in Pigs

Encephalomyocarditis virus (EMCV) and porcine circovirus type 2 (PCV2) are common causative agents with high infection rate in pig farms, thus a combined vaccine against both EMCV and PCV2 is highly desirable. In the present study, we developed an oil-adjuvant combination vaccine candidate comprising of inactivated EMCV and PCV2, and evaluated the safety and immunogenicity in mice and swine. The combination vaccine was found to elicit serum antibodies and had strong neutralization activity, more importantly, passive immunization with the combined vaccine protected swine against either EMCV or PCV2 lethal infections, whereas the monovalent vaccine only prevent the one of two virus challenge. Our results demonstrated the combined vaccine was safe and induced protective immune response in mice and swine as evident from sero-conservation as well as challenge studies in swine, indicating that component vaccines did not interfere with the immunogenicity of each other.