Vaccination has been widely used to minimize the economic losses caused by bovine herpesvírus type-1 (IBRV) and pseudorabies virus (PR V) infections. The traditional vaccines, however, induce a humoral response that is indistinguishable from that induced by the natural infection. The impossibility of distinction between vaccinated and naturally infected animais has impaired the establishment of control and eradication programs for these diseases. In the last years, the genetic manipulation of infectious agents has allowed the development of mutants that are detective in expression of specific envelope glycoproteins. The strategy consists of deletion of one or more non-essential viral envelope glycoproteins and the use of these mutants as vaccines. By using a serologic test that is specific for the deleted glycoprotein, it is possible to differentiate the vaccinated animais from those that have been naturally infected. The use of these genetically engineered vaccines, also known as marker vaccines, has been the basis for control and eradication programs of Aujeszky's disease in several countries and has recently begun to be utilized for IBRV. This article presents a brief review on the molecular and biological basis of the differential vaccines against IBRV and PRV and the possible applications of such vaccines in the control of these infections in the near future in Brazil.
bovine herpesvírus-1; bovine rhinotracheitis; Aujeszky's disease; pseudorabies vírus; vaccines
