Protective efficacy of vaccination by recombinant vaccinia virus against Neospora caninum infection

Abstract

The recombinant vaccinia viruses expressing the surface protein of Neospora caninum tachyzoite, NcSAG1 or NcSRS2, were constructed. The vaccination with these recombinant viruses could protect effectively the parasite invasion in a mouse model system. The vaccine efficacy of NcSRS2 was higher than that of NcSAG1. The present study indicated that a high level of IgG1 Ab production to parasite is important for clearance of parasite at the early stage of infection and that T cell response has a crucial role for protection against the intracellular infection at the late stage of infection. The recombinant vaccinia viruses might be applicable as vaccine against N. caninum infection in a natural host.