SUCCESSFUL PSEUDORABIES VACCINATION IN MATERNALLY IMMUNE PIGLETS USING RECOMBINANT VACCINIA VIRUS-VACCINES

Three gilts were vaccinated with a NYVAC vaccinia recombinant expressi ng glycoprotein go of pseudorabies virus (PRV) (NYVAC/gD). After farro wing, the piglets were allowed to nurse normally to obtain colostral i mmunity and then were divided into four groups, receiving NYVAC/gD, a NYVAC recombinant expressing glycoprotein gB of PRV (NYVAC /gB), an in activated PRV vaccine (iPRV), or no vaccine. The piglets were vaccinat ed twice, three weeks apart beginning at approximately two weeks of ag e and later challenged with virulent PRV oronasally. Piglets that rece ived NYVAC/gB or iPRV were the best protected based on lack of mortali ty, lower temperature responses, decreased weight loss and decreased v iral shedding after challenge. These results indicate effective strate gies for stimulating active immune response while still under the prot ection of maternal immunity.