Vaccine efficacy of recombinant feline herpesvirus type 1 expressing immunogenic proteins of feline calicivirus in cats.

We previously constructed a recombinant feline herpesvirus type 1 (FHV1), C7301dlTK-Cap, which contains an entire open reading frame encoding the capsid protein of feline calicivirus (FCV) F4 strain in the deleted locus of the thymidine kinase (TK) deficient mutant (C7301dlTK) of FHV1. In this report, we carried out in vivo experiments to assess the vaccine efficacy of the recombinant C7301dlTK-Cap against FCV and FHV1 infections in cats. As a result, two vaccinations with the C7301dlTK-Cap by intraocular, intranasal and oral routes protected cats to a significant degree against subsequent virulent challenges with both parent FCV F4 and FHV1 C7301 strains. The results are applicable for the further development of a new genetically engineered polyvalent vaccine for cats.