Vaccination with recombinant vaccinia virus vaccines expressing glycoprotein genes of pseudorabies virus in the presence of maternal immunity

Piglets which had received colostral antibody to pseudorabie virus (PRV) were divided into four groups and inoculated with a NYVAC vaccinia recombinant expressing glycoprotein gD of PRV, a NYVAC recombinant expressing glycoprotein gB of PRV, an inactivated PRV vaccine, or no vaccine. The piglets were vaccinated twice, 3 weeks apart, beginning at approximately 2 weeks of age and later challenged with virulent PRV oronasally. All three vaccines protected similarly when no maternal antibody was present. Although all three vaccines induced some active immunity in piglets with maternal antibody, piglets receiving the NYVAC/gB vaccine were the only ones protected similarly whether or not they had maternal antibodies to PRV.