Submitted to: Institute for International Cooperation in Animal Biologics
Publication Type: Proceedings
Publication Acceptance Date: May 15, 1997
Publication Date: N/A
Technical Abstract: Pseudorabies (PR), also known as Aujeszky's disease, is a viral infection which is a major problem for the swine industry worldwide. Piglets are the most severely affected by the disease, and the outcome of infection is often fatal in suckling piglets with no maternal immunity. Infection of mature pigs may cause respiratory signs or be subclinical but leave the host more susceptible to secondary infections. Pseudorabies virus (PRV) can also cross the placenta in pregnant swine and result in death of fetuses at any stage. Swine that survive initial infection become latently infected carriers of PRV and thus serve as its primary reservoir. Pseudorabies virus is a herpesvirus with a genome that is approximately 150 kbp and encodes at least 70 proteins. Glycoprotein peplomers which stick out from the envelope carry out important functions for the virus and serve as important antigens recognized by the host's immune system. The glyco- proteins are important in stimulating protective humoral immunity and may have a role in inducing cell-mediated immunity as well. Vaccines have been developed which have deletions in genes for certain glycoproteins, most often gE. Differential tests which detect whether or not antibodies to gE are present can thus distinguish between vaccinated and naturally infected pigs. With the advent of gene deleted vaccines and companion differential tests, vaccines have been approved for use in many of the current eradication programs. The benefits of using current vaccines such as lessening clinical disease, decreasing viral shedding, and increasing the threshold for viral transmission justify their use in many instances. Research is still being done in an effort to provide the best vaccine possible.