Comparison of different prime-boost regimes with DNA and recombinant Orf virus based vaccines expressing glycoprotein D of pseudorabies virus in pigs

Both DNA and Orf virus (ORFV; Parapox virus) based vaccines have shown promise as alternatives for conventional vaccines in pigs against pseudorabies virus (PRV) infection causing Aujeszky's disease. In the present study we evaluated the efficacy of different prime-boost regimes in pigs in terms of immunogenicity and protection against challenge infection with PRV. The different prime-boost regimes consisted of the homologous prime-boost regimes (DNA followed by DNA or ORFV followed by ORFV) and the heterologous prime-boost regimes (DNA followed by ORFV and ORFV followed by DNA), all based on glycoprotein D (gD) of PRV. Moreover, we compared the efficacy of the different prime-boost regimes with the efficacy of a conventional modified live vaccine (MLV).